A young man came to see me recently for what I thought was a business meeting. When I saw that he was wearing tracksuit trousers and a T-shirt, I knew the deal was off. If he was serious about the project he'd have been less casual in his semiotics (the study of signs and signals and their interpretation).
Yes, we judge by appearances - and by the clothes that people wear. And we're correct in making such judgments, because dress codes send signals about our values, our intentions and, if you like, our degree of respect for others or for institutions.
I say this in all awareness that I have, personally, almost perfected the 'batty old dame' look, and I won't deny that it's deliberate.
I long ago decided that if you can't look beautiful and elegant, you might as well look interesting and eccentric. But of course, for special occasions, I make an effort to scrub up. For a funeral or a wedding, I'm not about to do the old hippy act.
You consider the signal you're sending when you're getting dressed for the day.
There's an ongoing row in the Dail in the Republic about what constitutes proper apparel for a parliamentary appearance, and the usual suspects - Mick Wallace always the lead actor - are considered to be offending against respect for the institution.
But are stuffy rules about wearing jackets and ties now out of date? Maybe they are. Maybe we're in a more freewheeling age where that cherished value of 'choice' is now the arbiter of everything.
I must say I was very pleased when Theresa May stood up in the House of Commons and decisively rejected the European Court of Justice's ruling that employees were banned from burkas - or any other symbol of religious apparel. "What a woman wears is a woman's choice," stated the PM. Quite so! Presumably, she wasn't, therefore, vexed when there were comments comparing her pins with those of Nicola Sturgeon when they had one of their competitive Anglo-Scots meetings, both photographed showing a degree of leg (and Sturgeon's being judged the more shapely, if shorter).
But these are the new rules: wear what you like, but be prepared for the consequences. If a lady shows an expanse of leg, it will be assumed she did so deliberately. In a world of choice, she could cover herself up from head to foot if she wanted to. I certainly don't subscribe to the view that a woman exposing her anatomy is asking for trouble; but a woman (or a man) who does so, has made that decision deliberately, and it's reasonable to assume, in the hope of admiration. Always excepting conditions such as very hot weather, or the beach.
This is entirely in line with radical existentialism. Make your choice, but don't go around whinging and moaning about the consequences of your choice. Should airlines ban passengers - as recently happened in America - for turning up in ripped jeans? Should schools enforce a dress code? The French are having a lot of trouble with adolescents turning up in mini-shorts, and the universal torn-jeans outfit. Should some financial corporations insist that female employees wear high heels?
An airline is a business, and a business can set their own rules for the behaviour of clientele.
A corporation has 'the right to choose' as well as an individual.
If they want to bar passengers wearing clothes they consider inappropriate, they're entitled to. It's not very liberal, and it may not be very good for their business in the final analysis. But it would be more illiberal to prohibit them from making that call.
Schools deal with young people, and dress rules can be just a point of discipline. Lads were sent home from my sons' school because their hair was too long. Later, the headmaster confided to me that the school wasn't the least bothered about hairstyles as such, they were just enforcing discipline.
Kids rebel and test boundaries, and it's a bad school which doesn't uphold some boundaries.
As for women being told they must wear high heels at work - I'd question that on health and safety grounds, and employees should feel free to object. But the reality principle also comes into play - do you want the job or not?
When I was a rookie journalist, I was told by my department head: "Remember, Mary, the editor is always right. Even when he's wrong, he's right. That's the only way a successful newspaper can function."
Decisions have to be made quickly and continuously, and there's no time for committee consultations. If you want to act independently, you'll have to 'box clever' and find a roundabout route to getting your own way.
Telling a woman to wear high heels is surely dictatorial, but she has the right to choose whether to comply or to box clever and find a way around it. Yet high heels, too, are a policy signal.
I'm due for another business meeting next week. I'll deduce the situation pretty swiftly by what she chooses to wear.