One of the most widely debated topics in Philosophy is the nature of reality and with it comes a longstanding argument between realism and idealism.
Is our perception real?
Realists believe that there is a concrete, measurable reality, irrespective of whether we are aware of it or not, and that this reality is accessed by our sense perception in a fairly accurate and truthful way.
On the other side of the debate are those who claim that our reality is more or less a mental construct and that we can never know how reality is, or what it is, because whatever we claim to know about, our reality is always limited and mediated by our sense perception and our internal representations of 'external reality.'
The sense database about our world