Reality

Introduction
In a conventional view of reality we base the idea of truth on foundation of sensible reality. This view is founded on perceptions and reflection upon perception of the world as we experience it. This view is related to but not identical to empiricism. Conventional reality is based upon perspectives, dependent on the point of view of whoever experiences it. For this reason it is conventional since it relies to some extent about our belief concerning experience and perceptions from a certain point of view. There could be as many perspectives as there are people. Some perspectives are highly organized conceptualizations of the world and constitute theories of reality. Because of the problem of regress, the problem of establishing a foundation of truth and reality is a condition underlying all disciplines, including mathematics. Historically, there have been many responses to the problem of regress. The desire to establish the underlying ground of reality, or part of reality, finds its basis of the history of science and philosophy.

Plato
In Plato, philosophy concerns itself with the nature of Being itself, "what is". Platonic philosophy distinguishes between "what is" and material existence. What is Real is "what is" in itself, the Forms. Here is derived the term "Platonic Realism." This view of reality grounds truth in a Being outside of material existence, the Forms. For Plato, viewing the forms does not depend on sensible perception but on another form of 'seeing' possible for the soul [Ψυχή], an inner sight capable of seeing the Beautiful and the Good.

In Plato being is itself and nothing but itself. The form of justice is simply justice itself. To define, we use predicates. A form would have no predicates in the usual sense since its definition would give you something that had the same thing on either side of the formulation. No matter what predicates you add to a thing in itself, for Plato, it remains the same. On the other hand, when we say that Mary has blue eyes and Bill has brown eyes, we are talking about a particular trait, not an essence we could call 'Mary.'

In this sense, in Plato, it is easier so see why knowledge is not 'acquired' but instead involves anamnesis. Real knowledge involves a vision of the shining of the Beautiful, its Eidos. Something in immanent, sensible experience reminds you of the 'thing itself.' You see a bed and this evokes the memory of the Idea of a bed, and so on. Knowledge is the extent to which you can connect the bed of experience to the Form of the bed.

So there is a form of the relation between numbers, the form of specific numbers, and the abstraction of 'number itself. In immanent existence, the forms are all mixed up in matter, predicates abound. The ability to locate reality varies depending on the profession. I may see a beetle climbing on a branch and think about bugs. If I am no entomologist I may not go to the specific Form of beetle, only the form in general. My inability to understand the intricacy of number does not prevent me from a vision of the form of 'number' in general or the abstraction but may prevent me from seeing the intricacy of their relationships.

It does not seem that there can be a chance in something like Beauty or Justice but in life these are all mixed up and we see them in varying degrees, as composed in matter, and able to be broken up, degrade, disperse, arise. The beautiful we experience is beautiful because it participates in the Form of Beauty, not in itself. So if I want to know if a a sunset is beautiful, I go to the Form that gives the sunset its beauty. The relation of the particular sunset to Beauty is temporary. The sun goes down. The beauty of the sunset cannot fade. Perception of beauty in this world involve establishment of a relationship with what is truly Beautiful. Unlike finite beauty, the Form of the Beautiful has not beginning or end, no temporal status. When we perceive the beautiful sunset as being present, we soon perceive the facts to be otherwise when it has gone down. In thinking Platonic Realism, we must get around the idea of causality. The Real does not come to be and cease to be in a material sense. The scientific cause of the 'appearance' of a sunset, the movement of the sun, may have to do with the movements of bodies in space. The Form of the sun or of a sunset has no underlying, temporal cause. When we experience the sunset, all that has happened, from the point of view of Platonic Realism, is an experience of the beautiful itself. The bond to the beautiful of the sunset or to the Form of the sun itself is real but it is not the thing itself in virtue of itself. It is the establishment of a temporary relation.

Conventional reality, for Plato, is less than satisfactory and knowledge of it can be categorized as doxa,the stuff of beliefs and opinions, rather than the act of real knowledge. This would take the form of a 'seeing' rather than an 'acquiring'. The norm by which to measure Reality is the Form. Knowledge is simply to apply the Form to sensible things as if the Form were a yardstick.