In Non-Duality there is no finite, no definition of things. There are no limits. There are not many separate things. There is only an Infinite One without division or limitation.
Someone might object and say, "But there are limits. I was born and I will die. Everything comes to an end. My body is separate from other bodies. I am a being in my own right. I can't know what others think." Let's have a real look at these assertions and see if we can find any true limits.
Although we may think and assume, "I was born and I will die," it's not really clear who 'I' am and when I was born or began. It's impossible to define who 'I' am. We may say, "I am this body," but this body is changing all the time. We could say, "I was born at 2am on 28th January 1971," but that's just the registered time that the baby emerged from gestation. The time itself is subjective, as it's based on a manmade timeframe. It may refer to a point in time, but even that point is vague and never completely precise. Furthermore, being born isn't the beginning of the human body. The beginning of the human body can't be found. We could trace it back to the parents, but there is a continual unending flow back through generations and generations. Even what we consider to be 'human' is in a continual flow of evolution. Its origins flow from forms that we would not describe as human.
We have an understanding of what it means to die. We could say this is where the body is no longer animated. But even this death is not clearly defined, and we cannot say precisely when it occurs. Rather it can be recognised that the human body develops from a long undivided line of humans. It builds itself up by consuming nutrients from the environment, then it fades and eventually returns to the environment from which it is always made. So being born and dying is not as finite as we assume it to be.
Does everything come to an end? Well certainly nothing lasts. Everything that appears in the world will indeed disappear. It may take seconds, minutes, or years, but everything comes and goes. That doesn't mean everything ends. Rather there is a continual flow of coming and going. For instance, consider a drop of water landing on a pond. This creates ripples that flow outward from the source. The ripples are high at first but they lose their amplitude as they travel. They slowly fade and the surface is calm again. The ripples don't really end. They slowly fade back to the natural state, whilst their energy is transferred.
Is the body separate from other bodies? Only relatively so. The body is made of solid, liquid and gas, and it is separated from other bodies mostly by gaseous air. The body's apparent solidity of form against the spacious air appears as separate from other solid bodies. But this play of density of vibration brings about the appearance of separation. Consider water poured into a bowl made of ice. They appear separate due to the temporary solidity of the ice. But if heat is applied the water and ice become one. So there is only an appearance of separation due to the apparent density of forms. We could confidently say that all humans and animals are not separate from planet Earth.
How do I know I am a being and there are other beings? This is only suggested by the apparent separation of forms, that we've just seen isn't strictly true. The sense of who I am is generally based on a vague identity with this human body. But logically it doesn't stand. This finite being that I think I am is not necessarily who I am. I can't really find where it begins and ends.
So Non-Duality understanding is that we are not separate beings. Reality is an infinite singularity. We are That. It is understood that our nature is Consciousness, and all that we know is experienced by, in and as Consciousness. But if we are one Consciousness, why can't I know what others are thinking?
This is a common question. The answer is in understanding that within Consciousness there is an apparent variation of density that brings about a sense of the finite. Just as the ice bowl can hold water, so can the apparently finite mind hold its own thoughts. Thoughts are relative to the mind in which they form. The apparent separation of minds prevents the sharing of thoughts. However, that's not to say that there can't be communication between the apparently separate minds. To use another analogy, minds are like branches on the same tree, all connected by the central trunk. The Infinite Consciousness that we truly are is like the central trunk, but also the whole of the tree.
It is Infinite Consciousness that is the shared reality of all seemingly separate finite minds.