 Impulse, as noted above, is a movement of the soul toward an object. Though these movements are subject to the capacity for assent in fully rational creatures, impulse is present in all animate (self-moving) things from the moment of birth. The Stoics argue that the original impulse of ensouled creatures is toward what is appropriate for them, or aids in their self-preservation, and not toward what is pleasurable, as the Epicureans contend. Because the whole of the world is identical with the fully rational creature which is God, each part of it is naturally constituted so that it seeks what is appropriate or suitable to it, just as our own body parts are so constituted as to preserve both themselves and the whole of which they are parts. The Stoic doctrine of the natural attachment to what is appropriate (oikeiôsis) thus provides a foundation in nature for an objective ordering of preferences, at least on a prima facie basis. Other things being equal, it is objectively preferable to have health rather than sickness. The Stoics call things whose preferability is overridden only in very rare circumstances “things according to nature.” As we mature, we discover new things which are according to our natures. As infants perhaps we only recognised that food and warmth are appropriate to us, but since humans are rational, more than these basic necessities are appropriate to us. The Greek term ‘oikeion’ can mean not only what is suitable, but also what is akin to oneself, standing in a natural relation of affection. Thus, my blood relatives are – or least ought to be – oikeioi. It is partly in this sense that we eventually come to the recognition – or at least ought to – that other people, insofar as they are rational, are appropriate to us. Cicero’s quotation of Terence’s line ‘nothing human is alien to me’ in the context of On Duties I.30 echoes this thought. It is not only other rational creatures that are appropriate to us, but also the perfection of our own rational natures. Because the Stoics identify the moral virtues with knowledge, and thus the perfection of our rational natures, that which is genuinely good is also most appropriate to us. So, if our moral and intellectual development goes as it should, we will progress from valuing food and warmth, to valuing social relations, to valuing moral virtue. Ideally, we’ll have the recognition that the value that moral virtue has is of a different order to those things that we were naturally attracted to earlier. We then come to see that virtue is the only good.