Today, I'd like to talk about the topic of human nature as part of a general discussion of our attempts to answer the significance of the limitations of our abilities to know ourselves. So, how is human nature relate to the phenomenon of self-knowledge? The phrase human nature is often taken to suggest that we have a nature flowing from our status as human beings. This is not normally thought to exhaust all that a person might want to know about herself or himself, but it would seem at least, according to many theories of human nature, to be an important substratum and important dimension of the whole story you'd like to have about yourself if you're engaged in self-understanding. It's a potentially important substrate, that is, if you're nature as a human being is such as to make you inherently prone to violence, or wickedness, or for that matter inherently prone to sympathy or generosity, then this would be a good thing to know on the way to self-knowledge because self-knowledge is not just knowledge of that but also the ability to make good use of that knowledge bordering on the phenomenon that we discussed earlier that is under the rubric of wisdom. The wise path that is to say would be to take the heat of what we can learn about our nature as human beings or as members of some other broader category. Then, to take measures to control, develop, or otherwise respond appropriately to the thing we've realized. Notice though that the phrase human nature is kind of a curious one. It suggests that we have an essence flowing from our status as human beings. But this idea that we have an essence that flows from our status as human beings is not one that we should take for granted, not the one whether we should take uncritically. First of all, for some people, talk of our nature may be a way of avoiding responsibility for things that are really more a matter of choice than things that happened to us. Furthermore, if we do have a nature, that's there to know. It may flow from our status, for example, not so much as human beings but rather it may be due to our status as great apes, or as primates, or mammals, or maybe even as chordates. That is to say, what's distinctive of us as human beings may not be that terribly interesting, it may be something that we share with members of a broader class such as that of mammals or great apes, for example. Nevertheless, a traditional way of thinking about human nature as being something that allows us to understand something distinctive of ourselves quite human beings is expressed by the poet Alexander Pope in his Essay On Man. He writes, "Know then thyself, presume not God to scan. The proper study of mankind is man. Placed in this isthmus of a middle state, of being darkly wise and rudely great, with too much knowledge for the skeptic side and too much weakness for the stoic's pride, he hangs between in doubt to act or rest, in doubt to deem himself a God or beast, in doubt his mind or body to prefer, born but to die and reasoning but to err, alike in ignorance, his reason such, whether he thinks too little or too much." Pope expresses a wide spread, widely accepted way of thinking here which is that the thing that we ought to study if we're going to be studying anything at all should be ourselves, and more precisely ourselves as human beings as opposed to ourselves understood as members of a broader category. So, that's one characteristic set of views but as I say it's not one that we should take for granted as self-evident but rather one that we want to start with as a subject for further investigation. As we think about the nature of human nature, it's also useful I think to discuss some other dimensions of various theories that you might have about it. Some theories about human nature will vary from one another in terms of how positive or negative they are. For example, some theories will be very positive in the sense of characterizing human beings in a very optimistic way. Whereas, others will tend to characterize human beings in a fairly negative way as being prone to violence, for example, destruction or selfishness. You might also have differences among theories of human nature characterized in terms of how complete or partial they are. Some theories might claim to tell you everything you need to know about yourself by telling you about truth about yourself quay human being that is about your nature. Others will be more partial and more sketching in that respect. Likewise, different theories of human nature will differ from one another in terms of how much they allow you to know the answer that is find out about yourself in either a priori or a posteriori terms. This is something that you can get by introspection, for example, or is it something that requires scientific or some other kind of empirical investigation. Likewise, is your theory of human nature one that's anecdotal based on your private experience, or the experiences of your friends, or is it something more rigorous depending upon controlled trials or something of the kind. Likewise, a theory of human nature might differ from another by taking a certain view about how malleable we are. To what extent are human beings even if they have a shape as it were, is that shape one that can change with greater or lesser effort? Likewise, as a theory of human nature could be one that's focused on actual facts about how things are or will be focused more on potentialities, and what we're capable of as opposed to how things actually go in the real world. Furthermore, we might also notice that human nature might be thought of as coming in layers. There can be something that you might consider primary nature, the nature that we are, for example, born with and will tend to develop if we develop normally. But on top of that there's something you might call second nature. This second nature is something that's in some sense built on the first as a sort of second layer. It's presumably built by means of training either explicit or implicit, and involves such things as the acquisition of habits, sensibilities, predilections, preferences, tastes, and so forth. So that by the time you're an adult, it might be difficult to look inside and discern those habits of yours, those characteristic ways that you have that are learned as opposed to those that somehow you were born with and that developed by virtue of your just happened to grow up. So, in addition to primary nature, there's second nature. I'm sure you've heard the phrase at least in English,"That was just a human nature," involves a kind of composite between primary or first and second nature as well where by the time we're adults it's difficult to tell the two of them apart.