Metaphysics
Aristotle is a dualist, but not cartesian.
Materialism, for many metaphysicians is a kind of default position. Science is not fit to answer the question however. Science is probably compatible with most solutions. Much scientism will boil down to materialism however.
There is either neutral monism, which argues that the underlying reality is neither spirit or matter, but a neutral reality without a proper name. This is often applied to Spinoza, though this is a debated topic. Spirit and mind are just properties of the underlying reality, known as God, Nature or Substance. Aristotle would call it the substance, the underlying independent reality, we could also call it Nature in the sense of grounding everything else, whilst we can also call it God because He is a self-causing ultimate existence, a causa sui.
What we call mind is just a modification of the underlying divine attribute.
Spinoza thinks we should give up both christian and jews illusion, because everything that exists is directly immanent to the one real reality.
Schopenhauer is also a kind of neutral monist, arguing that the fundamental reality is the will. Which is productive of every reality, including the reality of representations and material.
In 20th century you have people who believe in a metaphysics of energy. Some of them are physicists, other are philosophers, but they all claim that everything can be reduced to energy. It seems to not really be a genuine case of neutral monism however.
There is also non-neutral monism, called idealism. The most famous one has a pretty bad reputation; George Berkeley. Berkeley claimed that there are no bodies, and matter is an illusion. The material world only exists in our minds. Matter can be reduced to the ideas of the material things we have. Esse est percipi, to be is to be perceived. Self-perception allows us to exist, but extra-mental reality exists only insofar as it is perceived but God is always watching so everything is always perceived. The continuous impression of material reality is ultimately a divine idea that is produced in our minds. Berkeley follows from Locke’s empiricism, and argues that this is basically a trust only in the things in which we directly perceive. All there is are perceptions. It is easy to have an immortal soul then, and we have full moral responsibility for our actions and our thoughts. But the downside is the error theory of bodily reality. The most enthusiastic followers are video-gamers. For him this is a refutation of skepticism, because there is nothing we can doubt as long as we perceive it. The effects of existence are perfectly transparent. Many anti-skeptical epistemologists find this attractive. Therefore there have been attempts to read Berkeley as a pragmatist.
In Leibniz there is an underlying reality of infinitely many monads, which are spiritual entities, or minds, so he is probably closer to some kind of idealism, however Leibniz does not deny that bodies exist.
Kant tried to come up with a refutation of idealism in the 2nd critique of pure reason, in which he argues that ultimately we cannot refer to our own minds without relating ourselves to some external reality that ultimately has to do with our place in time. This is a transcendental argument; it may force someone to accept a premise they initially deny.
Kant things there is a difference between how things are and how they appear, whilst Berkeley argues there is not. Kant says that it is not a skeptical position, becaues it is not skeptical that we cannot know things we cannot know, but we can know it insofar as it is given to us.
Kant also argues that we know some things in themselves, like for example our own will. Because we know it in virtue of having it. Therefore we can know that there are things in themselves, because we know them from direct acquaintance.