Is there a single-word adjective for "having exceptionally strong moral principles"?

Question

Yesterday I was writing an English text and found myself unable to find a single-word adjective to characterize a man with very strong moral principles, so I had to reformulate the entire sentence.

I'm curious whether there is such an adjective in the English language at all.

Of course, I know the word "decent," but it sounds like "normal," "good," "not a crook," while I wanted something stronger to convey the idea that he's well above the average in this regard.

But I am not looking for a too pretentious word like "saint." Just a regular word to say that someone has substantially stronger moral principles than the average Joe.

Here are examples of intended usage:

I was supervised by a _______ professor. He always let me be the first author of my articles despite the common practice at the university.

She wants her daughter to marry an intelligent and ________ man who is an XXX party member. But to make her wish physically fulfillable, she must remove one of these three requirements.

Answer 1

Principled or high-principled [M-W]:

exhibiting, based on, or characterized by principle.

Example sentences:

• She took a principled stand on funding public education.
• a high-principled art expert who always told clients what he honestly thought their items were worth
• [...]Fishback was regarded as a principled officer who staked his future on protecting captors and captives alike[...]

Answer 2

One such word would be scrupulous, defined as

having scruples; being careful to do nothing morally wrong.

Answer 3

You could use virtuous

having good moral qualities and behaviour:

He described them as virtuous and hard-working people.

or

upstanding (the formal equivalent of @TaliesinMerlin's answer)

behaving in a good and moral way:

She is regarded as an upstanding citizen in the local community.

Answer 4

In the contexts you provide, the word irreproachable would work well. It is defined by TfD as:

Perfect or blameless in every respect; faultless

Answer 5

How about upright? Note that this word has been mentioned several times in the definitions of other words.

Merriam-Webster defines "upright" as follows:

1 a: PERPENDICULAR, VERTICAL
b: erect in carriage or posture
c: having the main axis or a main part perpendicular upright freezer
2 : marked by strong moral rectitude
an upright citizen

(Boldface mine.)

Answer 6

Integrity does have an adjectival form, integrous. It is rare, however, and its Wiktionary definition includes a usage note:

Integrity is much more common than its adjectival form, integrous. Most speakers and writers opt for an etymologically unrelated synonym — such as honest, decent, or virtuous — when trying to express the adjectival complement of integrity in its moral and ethical sense. ... To convey that one is of or marked by integrity, other adjectives may be used including upright and upstanding.

(Have a look at the Google Fights results)

So if you want to be understood, just use a synonym. This could be one of the (excellent) already suggested answers, or also conscientious, decent, honest, righteous, fair, just, or genuine.

Also, I'd like to highlight 'honorable':

1] deserving of respect or high regard 2] of great renown 3] entitled to honor or respect 4] consistent with a reputation that is not tarnished or sullied 5] characterized by integrity : guided by a keen sense of duty and ethical conduct (Merriam-Webster)

Answer 7

Righteous is a bit stylized, but I regularly use it myself when I'm willing to be poetic/flowery.

adjective

1. characterized by uprightness or morality: a righteous observance of the law.
2. morally right or justifiable: righteous indignation.
3. acting in an upright, moral way; virtuous: a righteous and godly person.
4. Slang. absolutely genuine or wonderful: some righteous playing by a jazz great.

noun

5. the righteous, (used with a plural verb) righteous persons collectively.

Partly I'm leaning on that slang usage which arises out of 1940's US jazz culture.

Example usage from a 2018 episode of the U.S. television show Elementary (S6, E12):

U.S. MARSHAL STRIDER LINCOLN: You'd like fugitive apprehension. It's righteous work.

Definition at Dictionary.com.

Etymology at Etymonline.com.

Answer 8

One colloquial word I've liked with this meaning is stand-up in "stand-up guy": (Oxford English Dictionary, stand-up, n. and adj.):

5. colloquial. Of a person: reliable, dependable, trustworthy. Frequently in stand-up guy. Occasionally also in extended use.

2013 A. Gibbons Raining Fire v. 65 Forget the tough exterior. Mick's a stand-up guy when you get to know him.

Usually that is said about someone who is provably dependable, that is, they have shown their trustworthiness. This usage is limited though. If you don't use guy, someone might think you're referring to, say, a stand-up comedian, or someone who does comedy on a stage in front of an audience. So saying this is clear:

She wants her daughter to marry an intelligent, stand-up guy

However,

(x) I was supervised by a stand-up professor

could require some rewording to ensure readers understand the professor is honest and not funny, e.g.,

The professor who supervised me was a stand-up guy.

Answer 9

How about simply moral ?

This evokes an image of someone whose main concern is doing things the right way. This also necessarily evokes a strictness and even boringness of outlook in the minds of more superficial people (and social challenge to the immoral, of course!) if morality is the only real concern.

In reality, morality has to balance several considerations - not least the law of unintended consequences from the actions based on a decision.

Answer 10

If you would also be OK with a noun, I suggest:

My supervising professor was a mensch. He always let me be the first author of my articles despite the common practice at the university.

Mensch (n.)

A person of integrity and honor.

Recent Web examples:
...
My Justin, who will always be the face of the Dodgers, was a mensch, a real human being, who along with his wife, Kourtney, did marvelously caring services for the entire Los Angeles community.

—Los Angeles Times, 23 Dec. 2022
M-W

Mainly US informal

A good, honest person.

I like him. He's a mensch.
Cambridge

In American English

A person, esp. a man, regarded as being honorable, decent, and responsible and having strength of character.

Webster’s New World College Dictionary, 4th Edition. Copyright © 2010 by Houghton Mifflin Harcourt.
Collins

A 'real man', the implication being of character and integrity rather than sexual or physical prowess.
Green’s Dictionary of Slang

A person (chiefly male) of stregth, integrity and honor or compassion

2004, Alan Hollinghurst, The Line of Beauty ... Lionel Kessler, relaxing perhaps on a Louis Quinze day bed, garlanded all round with lines of beauty, seeing welcome proof that his clever maligned young friend was a mensch.

2008, Dwight S. Huggins, Into the Greenhouse Vol. VI: Dreams, She was an Amerindian, and stout. She was a real mensch, […] a hard working person, who took pride in her job, which was to spray from an aerosol can a particular base.
Wiktionary

In German Mensch means "human being." In Yiddish...mensch continues to mean a human being but includes the connotation of an especially decent, ethical human being. This Yiddish usage of mensch has passed into American English (for example, "what a great guy his is—such a mensch!").
Aaron Gross; The Question of the Animal and Religion 2014

Answer 11

How about respectable?

I was supervised by a respectable professor. He always let me be the first author of my articles despite the common practice at the university.

She wants her daughter to marry an intelligent and respectable man who is an XXX party member.

respectable, adj. and n.
A. adj.
3. a. Of a person: having a good or fair standing in society, either because of status or (esp. in later use) through being regarded as having a good character, a reputation for honesty or decency, etc.
_{Source: Oxford English Dictionary (login required)}

 

Answer 12

This word altruistic comes to my mind.

altruistic adjective al·​tru·​is·​tic ˌal-trü-ˈi-stik
relating to or given to altruism:

a: having or showing an unselfish concern for the welfare of others altruistic acts/motives a generous and altruistic person

Source: Merriam-Webster

Answer 13

Incorruptible, honourable. It's generally more colourful to use a combination of words for that idea, incorruptible, steadfast, unflinching, unwavering virtue.

Answer 14

Let's look at each of your examples.

I was supervised by a kind professor. He always let me be the first author of my articles despite the common practice at the university.

I used the word kind in this example because the narrator is referring to an act of kindness.

She wants her daughter to marry an intelligent and trustworthy man who is an XXX party member. But to make her wish physically fulfillable, she must remove one of these three requirements.

I used the word trustworthy in this example. For a person to be trustworthy, they need to have high integrity and strong moral principles.

She wants her daughter to marry an intelligent and conscientious man who is an XXX party member. But to make her wish physically fulfillable, she must remove one of these three requirements.

We can also use the word conscientious in the second example. A person who is conscientious acts according to a strong and unerring conscience.

So my suggestions are kind, trustworthy, and conscientious.

Answer 15

The word zealous can be applied to moral virtue.

showing great energy or enthusiasm in pursuit of a cause or objective.

Answer 16

One word would be "righteous". Sometimes comes on a bit strong, so best used in true cases.

Answer 17

I was surprised only two people suggested ethical but not as their main answer? Seems a good fit to me although honest and kind works pretty well too.