GOD able, unlike fragile human bodies, and they are common to all educated people, unlike the private objects of sensation Seven and three make ten, for ever and for everyone Our knowledge of arithmetic is not derived from the experience of counting: on the contrary, we use the rules of addition and subtraction to point out when someone has counted wrong We are aware of rules that apply throughout the unending series of numbers, a collection more numerous than we could ever encounter in experience (DLA 22–4) Like arithmetical truths, there are ethical truths that are the common property of all humans Wisdom is knowledge about the supreme good: everyone wishes to be happy, and so everyone wishes to be wise, since that is indispensable for happiness Though people may disagree about the nature of the supreme good, they all agree on such judgements as that we ought to live justly, that the worse should be subject to the better, and that each man should be given his due (2 10 28) These ‘rules and guiding lights of virtue’, Augustine says, are true and unchangeable and available for the common contemplation of every mind and reason What is it that unites arithmetic and wisdom? After all, some mathematicians are very unwise, and some wise men are quite ignorant of mathematics Augustine’s response is surprising Far be it from me to suggest that compared with numbers wisdom is inferior Both are the same thing, but wisdom requires an eye Wt to see it From one Wre light and heat are felt as if they were ‘consubstantial’ so to speak They cannot be separated one from the other And yet the heat reaches those things which are brought near to the Wre, while the light is diVused far and wide So the potency of intellect which indwells wisdom causes things nearer to it to be warm, such as rational souls Things further away, such as bodies, it does not aVect with the warmth of wisdom, but it pours over them the light of numbers (DLA 11 32) What arithmetic and wisdom have in common is that both are true and unchangeably true and contained in a single unchangeable truth This truth is not the property of any human individual: it is shareable by everyone Now is this truth superior to, or equal to, or inferior to our minds? If it were inferior to our minds, we would pass judgements about it, as we may judge that a wall is not as white as it should be, or that a box is not as square as it should be If it were equal to our minds, we would likewise pass judgement on it: we say, for instance, that we understand less 279