Socrates thought no one can know the good yet fail to do it. And so akrasia, moral weakness, weakness of the will, is impossible. Aristotle sort of disagreed, claiming you can be a total douchenozzle knowingly and on purpose (EN VII.3). Aristotle’s disagreement (or agreement) with Socrates hinges on what it means to “know” in the first place. For, you can deceive yourself into thinking you know Empedocles, when the best you can do is drunkenly recite his verses. Analogously, with enough philosophical acumen, it seems you can find an argument to justify just about any moral turpitude.
Oxford philosopher Anil Gomes nicely captures the problem:
This wouldn’t matter if philosophy were simply neutral. I once argued for the election of a philosopher rather than an economist to a Research Fellowship on the grounds that the philosopher at least would do no harm. (I was ignored.) But things may be worse. Prime amongst the ‘transferable skills’ so lauded by philosophy’s proselytisers are those of drawing careful distinctions, of paying attention to small but subtle differences between cases.
The development of these skills is thought to be central to a philosophical education. (‘Oxford Philosophy: training tomorrow’s thinkers today.’) And when used effectively, they allow a clarity of thought shocking in its brilliance and precision.
But they sometimes lapse into institutionally sanctioned pedantry. And when they do, they have analogues in a particular kind of self-deception, that involved in rationalising our bad behaviour. It is easy for a philosopher, trained in the making of distinctions, to distinguish lying from reticence, as Kant did, when writing to a suicidal correspondent. Lying is contrary to the moral law, he claimed; reticence on the other hand…
Here is one use for philosophical thinking: to draw distinctions that make one’s immoral conduct seem permissible, even praiseworthy. It is the kind of thinking which justifies claiming light bulbs on expenses or pressuring one’s spouse into taking one’s speeding points.
It is as if philosophy provides the tools which enable us to do all that we do whilst looking in the mirror and saying: yes, you’ve done good.
The whole passage is worth a read.