I recognize that I'm probably a bit odd for an Atheist, heck, I'm a bit odd for a human. One of my many odd stances is in my denial of the Other. Notice the big "O" there? I'm talking about the Other in philosophical terms; that which is separate from the Self. I do not think it exists and I don't make any appeals to some of the crazy stuff that the usual proponents of of such statements usually resort to. There's no need for a collective unconscious. No need for a psychic connection between all things. No need for us all to be neurons in the mind of god. We just have to look at things from a scientific standpoint.
First things first, evolution is true. It is an accurate representation of how things come to be. We Atheists generally agree on this point. What sets humans apart from the other animals? I am distantly related to everything alive on this planet, so not very much. There's no mystical quality which makes humans unique. We just happen to posses an intellect of relatively high caliber coupled with the ability to use spoken language and manipulate tools. Simply put, we're all one big family, some of us are smarter, stronger or faster than others, but we're all related. If we consider that we are made up of chemicals, then we are also related to simpler chemicals which gave rise to us. We're even distantly related to the various elements and even the stars that produced them. We are the children of stars and even further than that, the children of existence itself.
Second, where do "I" stop and "you" begin? From a physicalist point of view, I am little more than a sack of chemical reactions. What is under, and including my skin is me. Or is it? If I grant that I am made up of chemical reactions, where do my chemical reactions end? I am actually very dependent upon chemical reactions that happen outside of me in a similar way that the cells within my body (small sacks of chemical reactions in their own right) must import and export portions of their reactions. I must take in food, water and air and expel waste in order to survive. That food was produced by a series of chemical reactions that could be said to be necessary for my survival. The same goes for the air and water that I also take in. All of the chemical reactions that I'm made up of are ultimately dependent upon the energy from the sun which is produced via chemical reactions taking place there. In a chemical sense, the line between you and I is very fuzzy at best and at worst isn't there at all.
But what if we meet a true Other? What if we meet an extra terrestrial which evolved from life that arose completely separate from life on Earth? What if they were from an alternate dimension so they aren't even part of our universe? So what? Sure, it seems at first as if these would be true Others and certainly they would be the closest things we could conceive that would deserve such a title. However, not even these count as true Others, at least not once we begin interacting with them. Imagine that life, and existence itself, is like a fractal (because that's what it is). It's a fractal produced by many parallel and iterative interactions. Once a true Other interacts with our fractal, the two become intertwined. Even if their roots are separate from one another, the branches braid together. We become one by knowing one another.
What about my mind? Surely, I can retreat and say that my mind is what I am. But what of the portions of my mind that I'm not aware of? My subconscious provides me with a lot of data, a lot of answers, which I have no control over. Without my subconscious, I could not think at all. But if we continue to think this way, the self retreats until it evaporates entirely. Could we really say that we are not at all? Then what is it that self awareness is aimed at? The fact of the matter is that my perception of self is limited by what my mind has access to. My consciousness does not have full access to my brain, which produces an illusion that my consciousness is separate from these things. but it's merely a limitation of what we can see. If I could link my mind with yours such that both our brains had full access to every last bit of information from each other. I'm talking down to the most basic subconscious level and all the way up to executive thought. Would you consider us two different people or simply realize that we are one entity with two bodies?
The concept of the Other is the result of a short-sighted vision of Self. In the end, I am forced to conclude that we are not separate at all. All of life, and indeed all of existence is connected. The distinctions we make between one thing and another are useful in pragmatic terms, but not as much in philosophical terms. In reality, we are all one. No crazy new age hippie woo woo required.