Developing as a Human

"May I realize truth and become one with truth." Sri Ramakrishna

What does it mean to be human?  We used to say it was because we used tools and other mammals and animals did not, but that has been disproved with watching ravens, chimpanzees and other animals.  So, what does make us human?  Perhaps it is our capacity to be introspective, although there is no prove that animals are not also introspective.  Whatever the purpose, I find comfort in discerning what is truth for me and what connects me with all other life.