There are three ways of knowing things, living or non-living:1) through the five senses,2) through senses aided by scientific instruments like microscope and telescope, 3) through the testing models developed and used in scientific research.
The five sense organs are;1) eye, 2) ear, 3) nose, 4) tongue and 5) skin. The eye sees the colours of the world. The ear hears the sound of the world.The nose smells the flavour of the world.The tongue tastes the sweetness, bitterness, etc. of the world. The skin feels the touch of the world. They are the gateways to the knowledge of the world; they are the windows to the world.
The microscope, telescope and all other scientific accessory instruments enable scientists to perceive the world beyond the normal reach of the senses but ultimately, indirectly through the senses.
We can see the planets and other gigantic heavenly bodies also indirectly with the help of the telescope.We can view the tiny germs through the microscope.
Models created by scientists predict the expected things based on the models and provide us with the knowledge of the reality. If they fail to do so, they are rejected.
The mystic too is believed be aware of a glimpse of the world and not the entire truth of it.His intuition or insight may be a ray showing a direction of the road to the truth of the reality.His insightful clue is misty and unreliable.
Bertrand Russell aptly says, ‘ Of the reality or unreality of the mystic’s world I know nothing…..’ ‘What I do wish to maintain– and it is here that the scientific attitude becomes imperative– is that insight, untested and unsupported, is an insufficient guarantee of truth, in spite of the fact that much of the most important truth is first suggested by its means’
Science uses the inductive(scientific) method for attaining the truth of the reality, whereas logic and mathematics apply the deductive method for discovering the truth of the premises or statements.
If anything is beyond the boundaries of the above means of knowing, that thing is unreal and belief in such an unreal thing- or a being- is a superstition.God, miracle, fairies, rebirth, disembodied soul, heaven, hell, magic, devil, astrology, etc. which are untestable and unknowable are unrealities and superstitious beliefs of the human imagination. They are illusions, concepts formed without evidence.