I’ve been thinking more about how we are related to other animals, and about how we relate to animals. An essay by Herbert McCabe, called Animals and Us, is particularly interesting.

He affirms that animals clearly have emotions – they grieve, rejoice, even fall in love. The main difference between their ‘sensitive life’ and ours (‘sensitive’ meaning the life that comes from having senses) is not, then, of kind but of intensity – and intensity meant in a certain kind of way, not along an axis of pleasure/pain, but rather in that we can transcend our sensitive life, to some degree, in language.

The difference language makes can be thought of in terms of the metaphor of the network. All animals capable of a sensitive life have a nervous system, the medium of feeling, you might say. Humans, though, appear to be alone in having another kind of network within which their sensitive lives operate too, namely that of language. So whilst the sensitive lives of higher animals are probably quite similar, because the nervous systems are similar too, the abilities that come with language can still be thought of as adding a radically new dimension to the experience of life. McCabe calls this dimension ‘understanding’: linguistic animals, such as ourselves, understand in a way that non-linguistic animals don’t – though that’s not to say, of course, that our understanding is complete. Far from it.

What then is it to have a sensitive life, beyond just experiencing senses? It is an ability to find meaning in the world. Animals interpret the world via their senses and so live in meaningful worlds. Plants, presumably, do not. This might be called sensual meaning.

Language adds something new since it is based not on the senses alone but on an intellectual and linguistic interpretation of the world too. Language requires a certain biological substratum – like vocal cords, a brain and so on – but it primarily exists in the non-biological world of history, tradition and community. One obvious capacity that this additional mode of life generates is the capacity to ask questions and seek answers.

Today, there is a huge debate about how in control humans are of their linguistic world of meaning – whether or not they follow reason, exercise free will and so on? There is a fashionable tendency to play it down to almost nothing, to say that emotion rules the human animal, and that reason is just a delusion. Better, it seems to me, is to find a middle way between the two extremes of pure rationalism and pure emotivism.

Thomas Aquinas has a helpful way of talking about it. In addition to the five biological senses, he suggests that we need to add four more. A first would be the ‘coordinating sense’ that generates meaning out of the five biological senses. There is then a sense that recalls other senses and links that dimension in, which he calls the ‘imagination’. There is the ‘evaluative sense’, which assesses and weighs up. And fourth, there is the sense called ‘memory’.

I guess these extra senses would be meant in the same way as when we say ‘that makes no sense’ or ask ‘is that sensible?’ We are clearly not referring to the five, biological senses in those cases, but neither are we referring solely to reason; it’s something more intuitive than that.

I think this broader notion of senses might also help understand some of those moral dilemma questions beloved of experimental philosophers – the ones that ask whether you would prefer to push someone off a railway bridge to stop a truck that will otherwise kill five, or flick the points so that the truck kills one rather than five, or whatever it is. (Such experiments are all so wildly unlikely in real life that I wonder anyone ever takes them as serious comment on real life.) Given that this a question even worth asking, Aquinas’ four senses would suggest that it is easier to act when fewer of the nine senses are overloaded by the moral dilemma.

Better, think of making a decision. What this analysis suggests is how that could never be a pure act of reason, though reason has a part to play in shaping the four new senses. What you get then is a subtle interplay of all nine senses. The distinguishing characteristic that language gives us is that by enabling us to step back from our sensible lives, at least to a degree, we can decide otherwise. This would suggest that a non-linguistic animal might hesitate or cease to will to do something, but it cannot decide not to do something. McCabe calls this ‘free decision’ to distinguish it from a more simplistically conceived ‘free will’.