The external stimuli is exactly reality.
The word can't refer to both
what is, and to
what we think is, is, at the same time. That's far too confusing. Especially if you try to differentiate them as being "objective" and "subjective" reality. Because it's ALL SUBJECTIVE, to us. We are the 'subjects' of the subjectivity, after all.
Yes, our central nervous system must put the data together is a usable way and create a useful understanding of the external world. But that does not mean that we are completely unable to pin down any facts about reality. Comparing the observations of millions of different observers, as well as building tools to detect and examine reality beyond the limits of our biological senses, all give us knowledge of reality.
Yes, but that "reality" is still the one in our heads. And is still based on functionality within the unfathomable sea of stimuli that we call "existence". So we have not fathomed that unfathomable sea of existence, at all, really. We've simply gotten a little bit better at functioning within it. Are you getting what I'm saying, here? Increased functionality does not equate to existential truth. And this is why as we humans get cleverer, we aren't getting wiser. And this is becoming a serious problem for us.
Belaboring the point that we don't know it all yet does not mean we do not understand some of it.
Understanding requires both functional effectiveness
and the wisdom of application. We are not gaining in both.
Why, the mission of understanding reality of course.
That is not being achieved via science.
What we do with our knowledge of reality is a separate issue altogether.
That is the more crucial aspect, however. Far more crucial than obtaining functional control. Having a loaded gun is of no real value to us unless we know why and when to apply that functionality. (And why and when not to!)
If you are wanting to put the genie in the bottle and turn humanity back to a more ignorant and primitive time because you do not like the direction our increase understanding of reality is taking us as a species, then all I can say is it's too late. There is no turning back the clock. People are not going to stop their pursuit of knowledge and efforts to increase our understanding of reality. You need to focus your attention on human behavior and social psychology and use the realities found there to improve our existence in this closed system we call planet earth.
We need to stop building bigger and better guns until we figure out why and when to use them. Or we are surely going to kill ourselves with them.
And by "guns" I am referring to physical functionality: our ability to control and manipulate our physical environment.
It is only by understanding reality that we will truly know what the truth of our existence is.
That is patently false. And all of human history has shown it to be so. Functionality does not lead us to wisdom. In fact, history shows that it far more often leads us to self-destruction.
And whatever that truth, we have to deal with it as it is, not as we wish it to be.
This is also patently false. Positive change does not happen by our accepting what it. It happens by our seeking what could be, instead of what is.
You also have this tendency to imply there were halcyon days in the past that are somehow lost through our expanding understanding of reality. All throughout our history, there has been cruelty, injustice, war, greed, etc. It will only be through our scientific acknowledgement and understanding of our inherited instinctual behaviors that we will ever begin to solve these problems. This is the truth of our existence.
It is the effect of our fear and ignorance, not the "truth of our reality". And increasing our functional effectiveness only makes it more likely that we will annihilate ourselves. We need to start increasing our wisdom: gaining applicable knowledge of that "truth of our existence". And the scientific method cannot help us with this. We need philosophy, art, and religion.