One of the more potentially pernicious ideas in philosophy is the idea of “common sense,” so often played as a trump card against any idea that departs from the established prejudices of one’s interlocutors. But for the most part, that’s all “common sense” can amount to: prejudice, the pre-judgements shared in common by a given social context. Now this doesn’t necessarily make it bad. Hans-Georg Gadamer tried to “rehabilitate” the concept of prejudice (Vorurteil) on the grounds that even newly acquired knowledge must be measured against knowledge we already have. We must start where we are. As I noted in discussing dialectical and demonstrative argument, this is true even of foundationalist thinkers like Descartes who try to begin everything from first principles – in the chronology of their arguments, they must start with prejudice or “common sense” in order to figure out what the first principles are.
But Gadamerian prejudices can still be prejudices in the pejorative sense as well. Common sense is common only to a given social context; it is not common to humanity in general, and it is often not very sensible either. What was common sense to our ancestors – that the sun revolved around the earth, that women are intellectually inferior to men – is absurd to us, and within a couple hundred years our common sense will look absurd too. This is to be expected, for we are finite and limited human beings; we know what has been taught to us. But the more we rely on common sense, the more parochial our reasoning will be – the more we will be limited to our own context and the more absurd we will appear to future generations.
All of this is another reason why I think philosophy needs to consider historical context; we need to be aware of the big gaps between the common sense of other times and that of our own. What appears absurd to us did not appear absurd to others, and often for good reason. If our reaction to an important thinker’s apparently absurd claim is haughty dismissal, we close ourselves off to learning, and remain within the parochial shell of our own common sense, the sense that will be absurdity in two hundred years. But if – as Thomas Kuhn rightly advocated – we instead ask how an intelligent person could have made such an apparently absurd claim, then we may start learning about the assumptions taken for granted behind the text. And those assumptions may well teach us far more than anything the text explicitly claims.
Thill insisted on separating the history of ideas from their evaluation, in order to avoid genetic fallacies – the form of circumstantial ad hominem according to which explaining an idea serves to refute it or confirm it. Thill provides a good example of this in those vulgar Marxists who would identify an idea’s “bourgeois” provenance as sufficient to refuting it. Of course such fallacies are to be avoided. But the way to avoid this is not to juxtapose the premises of the arguments we read against our own assumptions, and immediately pronounce them false if they fail to match. Rather, to really find the truth in a text, we need to consider not merely what it says on the surface, but also the unspoken assumptions that gave rise to it, what phenomenologists might call its “taken-for-granted world” – its common sense, which will be so different from ours, and may be just what is needed to call our common sense into question.
For calling common sense into question, it seems to me, is one of the key tasks any philosopher is charged with. And this is often not a matter of mere abstraction. Common sense itself can be at the root of history’s darkest atrocities. Daniel Jonah Goldhagen has argued that anti-Semitism in early-twentieth-century Germany was simple common sense. One could differ on proposed solutions to “the Jewish problem,” but to say that Jews were just people like anybody else and posed no significant difficulties to the greater well-being of society – a view that has become common sense now – would have seemed the height of absurdity. Goldhagen’s view was more than confirmed to me when I read Marx’s famously anti-Semitic essay On the Jewish Question: this is not an argument for anti-Semitism, it simply assumes anti-Semitism. Everybody knows the Jews are a problem – that’s a given for the piece. But from that starting point, Marx argues that the real problem isn’t their religion, let alone their race, but the (supposedly) characteristically Jewish activity of “huckstering,” of capitalism. With such a view, Marx had managed to be several levels more enlightened than the common sense of his time, though not as much as we might hope with hindsight. But if we want to avoid the kind of atrocities that made perfect sense to Germans a few generations later, it is vital that we not limit ourselves to common sense as they did.