But we never tell the truth. We cannot properly 'tell' the truth, because our words are crude tools to express something, 'the truth', which may well exist, but which we cannot define.
Read not books alone, but men, and amongst them chiefly thyself. If thou find anything questionable there, use the commentary of a severe friend, rather than the gloss of a sweet-lipped flatterer there is more profit in a distasteful truth than in deceitful sweetness.