You're a gentleman and a scholar, kid.
--The Catcher in the Rye
The term gentleman (from Latin gentilis, belonging to a race or "gens", and "man", cognate with the French word gentilhomme, the Spanish gentilhombre and the Italian gentil uomo or gentiluomo), in its original and strict signification, denoted a man of good family, analogous to the Latin generosus (its invariable translation in English-Latin documents). In this sense the word equates with the French gentilhomme (nobleman), which latter term was in Great Britain long confined to the peerage. The term "gentry" (from the Old French genterise for gentelise) has much of the social class significance of the French noblesse or of the German Adel, but without the strict technical requirements of those traditions (such as quarters of nobility). This was what the rebels under John Ball in the 14th century meant when they repeated:
When Adam delft and Eve span,
Who was then the Gentleman?
John Selden in Titles of Honour (1614), discussing the title "gentleman", speaks of "our English use of it" as "convertible with nobilis" (an ambiguous word, like 'noble' meaning elevated either by rank or by personal qualities) and describes in connection with it the forms of ennobling in various European countries.
To a degree, "gentleman" signified a man with an income derived from property, a legacy or some other source, and was thus independently wealthy and did not need to work. The term was particularly used of those who could not claim nobility or even the rank of esquire. Widening further, it became a politeness for all men, as in the phrase "Ladies and Gentlemen,..." and this was then used (often with the abbreviation Gents) to indicate where men could find a lavatory, without the need to indicate precisely what was being described.
In modern speech, the term is usually democratised so as to include any man of good, courteous conduct, or even to all men (as in indications of gender-separated facilities, or as a sign of the speaker's own courtesy when addressing others).
Gentleman by conduct
Chaucer in the Meliboeus (circa 1386) says: "Certes he sholde not be called a gentil man, that... ne dooth his diligence and bisynesse, to kepen his good name"; and in The Wife of Bath's Tale:
Loke who that is most vertuous alway
Prive and apert, and most entendeth ay
To do the gentil dedes that he can
And take him for the gretest gentilman
And in the Romance of the Rose (circa 1400) we find: "he is gentil bycause he doth as longeth to a gentilman".
This use develops through the centuries, until in 1714 we have Steele, in Tatler (No. 207), laying down that "the appellation of Gentleman is never to be affixed to a man's circumstances, but to his Behaviour in them", a limitation over-narrow even for the present day. In this connection, too, one may quote the old story, told by some—very improbably—of James II, of the monarch who replied to a lady petitioning him to make her son a gentleman, "I could make him a nobleman, but God Almighty could not make him a gentleman".
Selden, however, in referring to similar stories "that no Charter can make a Gentleman, which is cited as out of the mouth of some great Princes that have said it", adds that "they without question understood Gentleman for Generosus in the antient sense, or as if it came from Genii/is in that sense, as Gentilis denotes one of a noble Family, or indeed for a Gentleman by birth". For "no creation could make a man of another blood than he is".
The word "gentleman", used in the wide sense with which birth and circumstances have nothing to do, is necessarily incapable of strict definition. For "to behave like a gentleman" may mean little or much, according to the person by whom the phrase is used; "to spend money like a gentleman" may even be no great praise; but "to conduct a business like a gentleman" implies a high standard.
William Harrison, writing a century earlier, says "gentlemen be those whom their race and blood, or at the least their virtues, do make noble and known". A gentleman was in his time usually expected to have a coat of arms, it being accepted that only a gentleman could have a coat of arms; and Harrison gives the following account of how gentlemen were made in Shakespeare's day:
Gentlemen whose ancestors are not known to come in with William duke of Normandy (for of the Saxon races yet remaining we now make none accompt, much less of the British issue) do take their beginning in England after this manner in our times. Who soever studieth the laws of the realm, who so abideth in the university, giving his mind to his book, or professeth physic and the liberal sciences, or beside his service in the room of a captain in the wars, or good counsel given at home, whereby his commonwealth is benefited, can live without manual labour, and thereto is able and will bear the port, charge and countenance of a gentleman, he shall for money have a coat and arms bestowed upon him by heralds (who in the charter of the same do of custom pretend antiquity and service, and many gay things) and thereunto being made so good cheap be called master, which is the title that men give to esquires and gentlemen, and reputed for a gentleman ever after. Which is so much the less to be disallowed of, for that the prince doth lose nothing by it, the gentleman being so much subject to taxes and public payments as is the yeoman or husbandman, which he likewise doth bear the gladlier for the saving of his reputation. Being called also to the wars (for with the government of the commonwealth he medleth little) what soever it cost him, he will both array and arm himself accordingly, and show the more manly courage, and all the tokens of the person which he representeth. No man hath hurt by it but himself, who peradventure will go in wider buskins than his legs will bear, or as our proverb saith, now and then bear a bigger sail than his boat is able to sustain.
Richard Brathwait's The Complete English Gentleman (1630) showing the exemplary qualities of a gentlemanIn this way Shakespeare himself was demonstrated, by the grant of his coat of arms, to be no "vagabond" but a gentleman. The inseparability of arms and gentility is shown by two of his characters:
Petruchio: I swear I'll cuff you if you strike again.
Katharine: So may you lose your arms: If you strike me, you are no gentleman;
And if no gentleman, why then no arms.
(The Taming of the Shrew, Act II Scene i.)
However, although only a gentleman could have a coat of arms (so that possession of a coat of arms was proof of gentility), the coat of arms recognised rather than created the status (see G D Squibb The High Court of Chivalry at pp 170-177). Thus, all armigers were gentlemen, but not all gentlemen were armigers. Hence Henry V, act IV, scene iii:
For he today that sheds his blood with me
Shall be my brother: be he ne'er so vile,
This day shall gentle his condition.
And gentlemen in England now abed
Shall think themselves accurs'd they were not here
And hold their manhoods cheap whilst any speaks
That fought with us upon St. Crispin's Day.
 Superiority of the fighting man
The fundamental idea of "gentry", symbolised in this grant of coat-armour, had come to be that of the essential superiority of the fighting man; and, as Selden points out (page 707), the fiction was usually maintained in the granting of arms "to an ennobled person though of the long Robe wherein he hath little use of them as they mean a shield".
At the last the wearing of a sword on all occasions was the outward and visible sign of a "gentleman"; the custom survives in the sword worn with "court dress".
A suggestion that a gentleman must have a coat of arms was vigorously advanced by certain 19th and 20th century heraldists, notably Arthur Charles Fox-Davies in England and Thomas Innes of Learney in Scotland. But the suggestion is discredited by an examination, in England, of the records of the High Court of Chivalry and, in Scotland, by a judgment of the Court of Session (per Lord Mackay in Maclean of Ardgour v. Maclean  SC 613 at 650). The significance of a right to a coat of arms was that it was definitive proof of the status of gentleman, but it recognised rather than conferred such a status and the status could be and frequently was accepted without a right to a coat of arms.
The Far East also held similar ideas to the West of what a 'gentleman' is, which are based on Confucian principles. The term "Junzi" (??) is a term crucial to classical Confucianism. Literally meaning "son of a ruler", "prince" or "noble", the ideal of a "gentleman", "proper man", "exemplary person", or "perfect man" is that for which Confucianism exhorts all people to strive. A succinct description of the "perfect man" is one who "combine[s] the qualities of saint, scholar, and gentleman" (CE). (In modern times, the masculine bias in Confucianism may have weakened, but the same term is still used; the masculine translation in English is also traditional and still frequently used.) A hereditary elitism was bound up with the concept, and gentlemen were expected to act as moral guides to the rest of society. They were to:
cultivate themselves morally;
participate in the correct performance of ritual;
show filial piety and loyalty where these are due; and
The opposite of the Junzi was the Xiaorén (??), literally "small person" or "petty person." Like English "small", the word in this context in Chinese can mean petty in mind and heart, narrowly self-interested, greedy, superficial, and materialistic.
Robert E. Lee
Lee's definition speaks only to conduct.
The forbearing use of power does not only form a touchstone, but the manner in which an individual enjoys certain advantages over others is a test of a true gentleman.
The power which the strong have over the weak, the employer over the employed, the educated over the unlettered, the experienced over the confiding, even the clever over the silly — the forbearing or inoffensive use of all this power or authority, or a total abstinence from it when the case admits it, will show the gentleman in a plain light.
The gentleman does not needlessly and unnecessarily remind an offender of a wrong he may have committed against him. He can not only forgive, he can forget; and he strives for that nobleness of self and mildness of character which impart sufficient strength to let the past be but the past. A true man of honor feels humbled himself when he cannot help humbling others.
That a distinct order of "gentry" existed in England very early has, indeed, been often assumed, and is supported by weighty authorities. Thus the late Professor Freeman (in Encyclopædia Britannica xvii. page 540 b, 9th edition) said: "Early in the 11th century the order of 'gentlemen' as a separate class seems to be forming as something new. By the time of the conquest of England the distinction seems to have been fully established". Stubbs (Const. Hist., ed. 1878, iii. 544, 548) takes the same view. Sir George Sitwell, however, has suggested that this opinion is based on a wrong conception of the conditions of medieval society, and that it is wholly opposed to the documentary evidence.
The fundamental social cleavage in the Middle Ages was between the nobiles, i.e. the tenants in chivalry, whether earls, barons, knights, esquires or franklins, and the ignobiles, i.e. the villeins, citizens and burgesses; and between the most powerful noble and the humblest franklin there was, until the 15th century, no "separate class of gentlemen". Even so late as 1400 the word "gentleman" still only had the sense of generosus, and could not be used as a personal description denoting rank or quality, or as the title of a class. Yet after 1413 we find it increasingly so used; and the list of landowners in 1431, printed in Feudal Aids, contains, besides knights, esquires, yeomen and husbandmen (i.e. householders), a fair number who are classed as "gentilman".
Sir Charles Mainegra
Sir Charles Mainegra gives a lucid, instructive and occasionally amusing explanation of this development. The immediate cause was the statute I Henry V. cap. v. of 413, which laid down that in all original writs of action, personal appeals and indictments, in which process of outlawry lies, the "estate degree or mystery" of the defendant must be stated, as well as his present or former domicile. Now the Black Death (1349) had put the traditional social organization out of gear. Before that the younger sons of the nobles had received their share of the farm stock, bought or hired land, and settled down as agriculturists in their native villages. Under the new conditions this became increasingly impossible, and they were forced to seek their fortunes abroad in the French wars, or at home as hangers-on of the great nobles. These men, under the old system, had no definite status; but they were generosi, men of birth, and, being now forced to describe themselves, they disdained to be classed with franklins (now sinking in the social scale), still more with yeomen or husbandmen; they chose, therefore, to be described as "gentlemen".
On the character of these earliest "gentlemen" the records throw a lurid light. Sir Charles Mainegra (p. 76), describes a man typical of his class, one who had served among the men-at-arms of Lord Talbot at the Battle of Agincourt:
the premier gentleman of England, as the matter now stands, is 'Robert Ercleswyke of Stafford, gentilman' ...
Fortunately—for the gentle reader will no doubt be anxious to follow in his footsteps—some particulars of his life may be gleaned from the public records. He was charged at the Staffordshire Assizes with housebreaking, wounding with intent to kill, and procuring the murder of one Thomas Page, who was cut to pieces while on his knees begging for his life.
If any earlier claimant to the title of "gentleman" be discovered, Sir George Sitwell predicts that it will be within the same year (1414) and in connection with some similar disreputable proceedings.
From these unpromising beginnings the separate order of "gentlemen" evolved very slowly. The first "gentleman" commemorated on an existing monument was John Daundelyon of Margate (died circa 1445); the first gentleman to enter the House of Commons, hitherto composed mainly of "valets", was William Weston, "gentylman"; but even in the latter half of the 15th century the order was not clearly established. As to the connection of gentilesse with the official grant or recognition of coat-armour, that is a profitable fiction invented and upheld by the heralds; for coat-armour was but the badge assumed by gentlemen to distinguish them in battle, and many gentlemen of long descent never had occasion to assume it, and never did.
Further decline of standards
This fiction, however, had its effect; and by the 16th century, as has been already pointed out, the official view had become clearly established that "gentlemen" constituted a distinct social order, and that the badge of this distinction was the heralds' recognition of the right to bear arms. However, some undoubtedly "gentle" families of long descent never obtained official rights to bear a coat of arms, the family of Strickland being an example, which caused some consternation when Lord Strickland applied to join the Order of Malta in 1926 and could prove no right to a coat of arms, although his direct male ancestor had carried the English royal banner of St George at the Battle of Agincourt.
In this narrow sense, however, the word "gentleman" has long since become obsolete. The idea of "gentry" in the continental sense of noblesse is extinct in England, and is likely to remain so, in spite of the efforts of certain enthusiasts to revive it (see A. C. Fox-Davies, Armorial Families, Edinburgh, 1895, The right to bear arms, 1900). That it once existed has been sufficiently shown; but the whole spirit and tendency of English constitutional and social development tended to its early destruction. The comparative good order of England was not favourable to the continuance of a class developed during the foreign and civil wars of the 14th and 15th centuries, for whom fighting was the sole honourable occupation. The younger sons of noble families became apprentices in the cities, and there grew up a new aristocracy of trade. Merchants are still "citizens" to William Harrison; but he adds "they often change estate with gentlemen, as gentlemen do with them, by a mutual conversion of the one into the other".
A line between classes
A frontier line between classes so indefinite could not be maintained in some societies such as England where there was never a "nobiliary prefix" to stamp a person as a gentleman, as opposed to France or Germany. The process was hastened, moreover, by the corruption of the Heralds' College and by the ease with which coats of arms could be assumed without a shadow of claim; which tended to bring the science of heraldry into contempt.
The prefix "de" attached to some English names is in no sense "nobiliary". In Latin documents de was the equivalent of the English "of", as de la for "at" (so de la Pole for "Atte Poole"; compare such names as "Attwood" or "Attwater"). In English this "of" disappeared during the 15th century: for example the grandson of Johannes de Stoke (John of Stoke) in a 14th-century document becomes "John Stoke". In modern times, under the influence of romanticism, the prefix "de" has been in some cases "revived" under a misconception, e.g. "de Trafford", "de Hoghton". Very rarely it is correctly retained as derived from a foreign place-name, e.g. "de Grey".
In Thomas Hardy's Tess of the D'Urbervilles, Tess Durbeyfield's travails stem from her father's discovery that his family name was in fact inherited from an aristocratic D'Urberville ancestor. Her apparent distant cousin (and seducer) Alec D'Urberville proved to be a member of a nouveau-riche 19th century family which had merely adopted the surname of "Stoke-D'Urberville" in the hope of sounding more distinguished.
Formal court titles
At several monarchs' courts, various functions bear titles containing such rank designations as gentleman (suggesting it is to be filled by a member of the lower nobility, or a commoner who will be ennobled, while the highest posts are often reserved for the higher nobility). In English, the terms for the English/Scottish/British court (equivalents may include Lady for women, Page for young men) include:
Gentleman at Arms
Gentleman of the bedchamber
Gentleman of the Chapel Royal
In France, gentilhomme *
... rendered as 'gentleman-in-ordinary'
... as gentleman of the bed-chamber
In Spain, e.g. Gentilhombre de la casa del príncipe 'gentleman of the house[hold] of the prince'
Such positions can occur in the household of a non-member of a ruling family, such as a prince of the church:
Gentiluomo of the Archbishop of Westminster
The word "gentleman" as an index of rank had already become of doubtful value before the great political and social changes of the 19th century gave to it a wider and essentially higher significance. The change is well illustrated in the definitions given in the successive editions of the Encyclopædia Britannica. In the 5th edition (1815) "a gentleman is one, who without any title, bears a coat of arms, or whose ancestors have been freemen". In the 7th edition (1845) it still implies a definite social status: "All above the rank of yeomen". In the 8th edition (1856) this is still its "most extended sense"; "in a more limited sense" it is defined in the same words as those quoted above from the 5th edition; but the writer adds, "By courtesy this title is generally accorded to all persons above the rank of common tradesmen when their manners are indicative of a certain amount of refinement and intelligence".
The Reform Act 1832 did its work; the "middle classes" came into their own; and the word "gentleman" came in common use to signify not a distinction of blood, but a distinction of position, education and manners.
By this usage, the test is no longer good birth, or the right to bear arms, but the capacity to mingle on equal terms in good society.
In its best use, moreover, "gentleman" involves a certain superior standard of conduct, due, to quote the 8th edition once more, to "that self-respect and intellectual refinement which manifest themselves in unrestrained yet delicate manners". The word "gentle", originally implying a certain social status, had very early come to be associated with the standard of manners expected from that status. Thus by a sort of punning process the "gentleman" becomes a "gentle-man".
In another sense, being a gentleman means treating others, especially women, in a respectful manner, and not taking advantage or pushing others into doing things they choose not to do. The exception, of course, is to push one into something they need to do for their own good, as in a visit to the hospital, or pursuing a dream one has suppressed.
In some cases its meaning becomes twisted through misguided efforts to avoid offending anyone; a news report of a riot may refer to a "gentleman" trying to smash a window with a dustbin in order to loot a store. Similar use (notably between quotation marks or in an appropriate tone) may also be deliberate irony.
Another modern usage of gentleman- is as a prefix to another term to imply that a man has sufficient wealth and free time to pursue an area of interest without depending on it for his livelihood. Examples include gentleman scientist, gentleman farmer, gentleman architect, and gentleman pirate.