What am I? There are a number of possible answers: I am a person, a mind, a human animal, a soul, part of a human being (e.g., a brain), I do not exist, and even more. Philosophers have been asking this for thousands of years and were not satisfied. In the contemporary analytic tradition, philosophers are attracted to a naturalistic, scientific ontology hence a materialistic personal ontology that matches the huge success in scientific discoveries. They think that we are material objects. However, their views do not match our intuition about some cases regarding our survival. Also, the possibility of an afterlife is eliminated. In my thesis, I explain the shortcomings of current philosophical theories, and develop a better account. I propose the Conscious Subject View, according to which (1) I am a subject of experience, a mental entity whose essential property is to be conscious, and (2) Subjects have haecceities, a property that makes an object a different object from other objects even if they are qualitatively identical with it. I provide two arguments for the claim that we are essentially subjects. The first is the Essentiality Argument. I first define an egoistic concern as one such that necessarily, my concern about X can be egoistic if and only if I exist and persist as X. Furthermore, I argue that necessarily, I can be egoistically concerned with an entity E if and only if E is numerically identical with my subject of experience. I then conclude that we are essentially subjects of experience. My second argument, which I call the Argument of Persistence, is that we have the intuition that we persist only when there is the gradual replacement of the brain. I argue that the best candidate to explain this intuition is that we persist as subjects of experience. I further offer a conceivability argument for the claim that haecceity of the subject determines its persistence. I defend a mentally-oriented proposal regarding our nature by examining the essential properties of our existence. It solves most of the problems with the materialistic personal ontology and shows the theoretical advantages of a long-neglected approach.