There are five widely known senses.
Sight, hearing, touch, smell and taste.
We've got some minor ones as well, such as balance, temperature and many more.
However, people fail to realise that there's also the sixth major sense. Thoughts themselves.
If we look closely, all these five senses have the same base. Specified cells in eye react to energy of light, cells of ear recieve energy in form of air's vibrations, skin cells pick up energy of mechanical changes, and so tasting and hearing depend on translation of certain substances' chemical energy.
These cells in different organs differ in their structure and the way they appear, however, if we stop looking at them in such small scale, we can see that ALL of the cells or organs responsible for any sense translate the energy.
So, a light enters the eye, certain wavelenght of certain energy stimulates the eye's rod or cone cells with a certain intensity. Then the energy of light is translated to energy of electrical impulse, which goes straight to the brain, creating the sensation of sight.
If it comes to smell, a certain particle enters the nose, binds to a smell receptor cell, and the chemical energy of this particle is, again, translated to energy of electrical impulse, which goes straight to the brain, creating the sensation of smell.
Now, let's move to the crucial part. The sense of thoughts.
During the creation of thought, pathways in our brain that collect memories(and many more known or unknown pathways) connect. First, there's this spark of electricity, that moves all along the neuron and releases a dose of neurotransmitters(amount of different NTs is equiavlent to strength of this spark, basically resulting in "creating" various thoughts).
Then, chemical energy of NEUROTRANSMITTER is translated to energy of electrical impulse, which happens in the brain, creating the sensation of thought.
Therefore the 'sense of thoughts' reacts to and is stimulated by neurotransmitters themselves, with receptors on neurons' membrane being receptors of the stimulus. So, kind of like smell, the stimulus is chemical, compared to sight, where it's electromagnetic wave; anyways the result in all of these is electric impulse in neurons (hence the idea of "thoughts" as a sense, due to the same basic layout; transfer of energy).
The 'smell particle' connects to receptor and is translated to a certain amount of neurotransmitters/certain strenght of neuronal impulse. SO, again, we can see that when the first outer layer of this communication is cut off, we're left only with the neurotransmitters and impulses themselves. Anyway, the transduction of energy remains.
If it comes to "sense of thoughts" the receptor lies within us, whereas in sight or smell or touch it's external. However, does it matter if it's on the surface of skin or under it if it all comes down to neurons of our brain?
When you lie in a dark, silent room, without any external stimuli, you still retain your thoughts, colorful, vivid or complex. All the magic of the brain - still happens. So, how isn't it a separate, full-fledged sense?
