What is a Person?

I have wondered, for quite some time, what a "person" is. Traditionally speaking a "person" is a human being. But legally speaking a corporation is also a person and children sometimes are and other times they are not (for example they are not allowed to enter into legal contracts). This brings about many questions on limitations to personhood. I have been thinking on this for awhile and I cannot come up with a universal definition of "person" that works in all legal circumstances. I have, however, developed the following definition of a "person" that I feel should be applied in the context of contract law: Person: noun. A singular entity which issued aware and capable of reason with the ability to comprehend the outcomes of their decisions and communicate their wishes. Each and every contract should be something that any "person" can engage in. If the contract requires agreement between two or more entities then any "person" should be able to make the agreement for themselves. This definition of "person" is not racist, nor sexist, nor sexual-preference-ist, nor even speciesist: it is entirely about whether the participant in the contract is able to reason out the ramifications of their choice and communicate their choice to enter the contract to others. I welcome suggestions on a better definition of "person" that can be used across all areas of the law.