On what basis do we assume that people are similar?

Question

In philosophical discussions, when we e.g. talk about souls (mind-body problem) or consciousness, it is often assumed that people are similar. This is why we ask whether "we" have souls, or why "our" consciousness works. It is always assumed everybody is in the same boat, so to speak, and so the same answer must apply to us all.

But why should this be the case?

Why can't some people have souls and others cannot? Why can't some people have consciousness and others truly cannot? And even if we assume we all do have souls and consciousness, why assume they have the same function, the same source, the same purpose? If each soul and each consciousness is unique, surely it makes more sense to talk about unique answers?

If one insists that everybody is similar, then one also has to answer questions such as "do all living organisms then have souls and consciousness? What about bacteria then? Do they have souls? Or what about a donkey?" and the discussion quickly becomes unserious.

Answer 1

Guill's answer is pretty silly.

Just because humans are similar in terms of body does not make them similar in terms of the philosophical attributes we concern ourselves with her.

By the very nature of the existence of such philosophical attributes, they are distinct from bodily matters, and therefore correlation between bodily matters does not necessarily link to correlation between non-bodily matters.

One can think of these other matters as operating in a different dimension. We could e.g. have a number in 2 dimensions equal to (0,10) and another number equal to (0, 100000). On the 1-dimensional x-axis, these two numbers are 100% identical and both equal to zero. But that does not mean they have to be equal on the y-axis, where they are worlds apart.

Answer 2

I'd say:

1. The inductive argument Mauro suggests and attributes to Wittgenstein. (It can probably be dated further back). The behavior of these other humans is similar to what we can imagine.

2. a belief in kinds, categories or rules of the universe. Starting with the classic models in the West and East we have morphe/Form or xing 性 for a type of thing. Or if you prefer we have categories in ours head with which we group things. Or things follow natural laws and procreate things roughly similar to them.

3. A principle of parsimony in explanation. Given the similar behaviors, attributes, responses to medicine, etc. of these seemingly similar creatures, it can either be the case that they are in fact similar or that they are in fact different but appear very similar. Faced with these choices the better one (in terms of explanatory power, ease of living, consistency with rules and kinds) is to assume they are the same kind of thing.

Beneath all of this is a bigger question about skepticism against our natural intuitions and categories. Ultimately, this is a big choice between pernicious irresolvable skepticism and rule-based consistency.

There's quite a few arguments for the rule-based thing being constitutional to thinking. You can find versions of this in Kant, Hegel, and contemporary interpreters like Korsgaard and Habermas. You can also find similar protean ideas in Descartes's renunciation of radical skepticism in the Meditations and in Aristotle's general attitude.

tl;dr - you have a choice: skepticism that won't jive with anything (even the ability to write an argument that you expect others could read) or a default commitment to believing other humans are similar beings to yourself (if one has a soul, then all do; or if all need oxygen, then all do). Depending on which way you're avoiding radical doubt, you can explain exceptions in different ways.

Answer 3

The basis rests on at least two factors: 1) accumulated knowledge and 2) observation.

Through accumulated knowledge, it has been determined that our chromosomes (humans) are 99.9% the same.
Though observation, we see that we have two hands, two feet, two eyes, one heart, etc., etc,.

The conclusion that humans are very similar (at least physically), is inescapable!

With regards to uniqueness, all it takes is one thing different, among thousands (millions) of same things. This means "things" can be very similar, and yet, unique!

No, not all living organisms have souls/consciousness. Some "particular" requirements must be met.

Answer 4

Soul is a very confused category. Firstly, what is usually meant is immortal soul. In the ancient world all beings were indeed considered to have souls (look it up!), but only humans that latter. In Judaism the immortality of anyones soul is disputed. And in Christianity we can see the theology of the soul is more influenced by Plato than Judaism. Aristotle had a particularly clear way of explaining the multiple soul, with supervening layers - able to be a source of causation downward through the hierarchy. Rational soul, above sensative soul, above vegetative soul. He argued against the seperateness of any of these from the body. And described them as types of pattern or organisation, which can flourish or decay. This is very like emergent layers of organisation, consciousness, nervous & sensory systems, and cellular being. The idea that the soul is some kind of magic timeless ghost can be traced at least to Plato, but owes more in philosophical detail to Descartes, and his disproven untenable dualism.

Turing addressed the idea of when we should consider a computer conscious. There are in fact many disputes over the validity and precise implementation of the Turing Test, you might want to look this area up in relation to your scepticism (also 'philosophical zombies', which is exactly the area you are talking about). Turing basically argued if something can behave consciously, it is conscious. And all we can do is evaluate & interrogate behaviour, not speculate about some kind of innaccessible ontic essence.

As babies, we develop our consciousness relationally. The ability to decieve and understand that others may have false beliefs is a crucial stage of children's mental development, that occurs around 3 or 4 years of age, without which this scepticism could not begin. Looking back at our own development then, we can see how we have become more complex in relation to a society around us of individuals already displaying greater relational complexity. The scepticism about consciousness in others is further undermined by the Private Language argument, the sophistication of our thoughts depends on language, which was developed and learned relationally. We can't view ourselves as the disembodied rational minds of outdated philosophies.

Denying full consciousness or souls in others doesn't have a good record. It was used to justify enslavement of Africans and native Americans respectively (doubt about Americans having souls was justified by them not being mentioned in the bible, unlike Africans). Statements like "all men are created equal" are not just philosophical, grounded in the lack of evidence to the contrary, but also politically sophisticated antidotes to our tendency to try and diminish those we disagree or are in conflict with, or wish to exploit. Such relations with others may seem appealing to some in some ways, but history has amply shown them to be destructive of potential, corrosive or morals, and to lead inevitably to war revolution and violent civilisational collapse. Philosophical backing for this can be seen for instance through Rawl's theory of justice, where a society must be set up in such a way that we would consent to be born into any position in it (for that society to be just). If we are truly equal, then any people in our society now would be justified in acting as you would, in their position. If the social contract with them is voided, then revolt, war, or collapse, will begin unless justice is done, and seen to be done. No justice, no peace.