It’s usually a good thing to be truthful and to speak the truth, but the truth is not the same as the good. Most would agree, yet some believe that the good is numerically identical with the good. That strikes me as incorrect.
For, plainly, it does seem as if we can speak of factual truths, of scientific truths, and of mathematical truths without also having say that they are good. It may be a good thing to know that 2+2 = 4, but is that mathematical truth itself good? I don’t think so.
Yet both my Socratic and my Buddhist commitments do make me think that one sort of truth–to wit, metaphysical truth–is special in that it entails goodness. From a Buddhist perspective, if I perceive things clearly (which is to say: if I’m enlightened), this entails my acting with care for all sentient beings. For Socrates, if I have the special knowledge about the nature of things called wisdom, that is to say, if I can grasp how things truly are, this entails my acting virtuously. Just as emptiness (sunyata) entails care (karuna), so wisdom entails virtue.
So, I’m definitely committed to saying that metaphysical truth matters not just for its own sake (because it seems to me a basic human concern to be in touch with the way of things [Laozi puts the point nicely in Daodejing]) but also because such truth entails goodness. In this respect, I differ from those who believe that they are utterly disjunct (for them, it’s a contingent matter whether someone who is aligned with (say) scientific truth is also someone who acts virtuously) as well as from those who believe that they are identical. The former may lose too much by thinking that the truth bears no close relationship with goodness; that may be too much of a sacrifice.
The latter, however, worries so much about the devastating effects wrought by our technological age that they seek to solder truth to goodness and goodness to truth. While I admire their pangs of conscience, I don’t believe we need to make this move to get what we’re after. We can instead distinguish between kinds of truth, noting that the sort we should ultimately seek–I’m speaking again of metaphysical truth–is the kind that carries deep within it its own immediate implications for how we act as ethical persons and for how we treat the natural world.