I think intellectual honesty demands that philosophers accept this all-pervading normativity more openly. Apart from anything else, this helps explai… - Julian Baggini

That is why there can be no one account that is ‘the truth’, not because ‘truth’ is beyond us. We need to distinguish between an account which is ‘the truth’ and one which is ‘truthful’. If by ‘the truth’ of a life we mean the one, true, complete account of it, then no such truths can be told. But we can tell more or less truthful stories about our lives and those of others: ones that do not gloss over embarrassing facts, ones that reveal many sides of a personality and not just those we wish to promote. Relating such a truthful story is not about cataloguing the largest possible number of true facts about a person. That is why our commitment to truth and rationality requires that our conceptual maps only include genuine features of what we are mapping and do not leave out anything that a user of that map might reasonably be expected to find useful. But the idea that we can come up with any kind of conceptual map that does not reflect our values and interests is a mirage. Philosophical autobiography helps us to see that behind all reasoning is a reasoner who can never drain away all her individuality.

Think of any serious participant in intellectual life. Is there any who does not try to be as comprehensible as is possible? Many are so incomprehensible that we doubt them, but this is almost always a failure of execution, not a success born of intent. Does anyone assert that it is not possible for anyone else to assess the merits of their claims? Very few, and the whole raison d’être of publishing and discussion is precisely that others are, in principle, capable of assessing what they have read or heard and sharing these assessments. Does anyone declare that what they have to say is wholly relative to the interests only of a particular sector of society? Surely not. Even as we acknowledge our biases and partial perspectives, we strive to overcome them as much as is possible. Does anyone think there is no way they could possibly be wrong about what they believe? We may sometimes feel this, but the fact that we nonetheless leave ourselves open to criticism and take those criticisms seriously shows we are committed to the idea that rational inquiry demands we treat our beliefs as defeasible. And finally, when you have seen someone provide what seem to you good reasons for their accepting their position, is your agreement not in some sense involuntary? Similarly, can you not help but dismiss arguments that seem to you weak or ill-founded?

To answer this requires knowledge of ‘child development, healthy emotional lives, healthy cognition and what is going to equip children to become high-functioning adults’, and ‘there are scientific truths there waiting to be discovered’. But again, this only implies that scientific knowledge can inform ethics, not that it can determine it. Similarly, we can learn from a neuroscientific point of view why it is that heartbreak feels so bad, but neuroscience can’t tell us if it is worth taking the risk of paying that price by opening ourselves up to love.