"the main opposition to rationalism is empiricism, the view that sense experience is the source of knowledge"
- Rationalism
The belief that reason and logic are the primary sources of knowledge or intelligence, and that some truths are available to be grasped directly through the intellect, the intelligence. Rationalists believe that knowledge, the intelligence from it, is independent of sensory, transmitted or perceived by the senses or experience. Logically manifestation is through the Will, the Power of the Selected spirit choice.
- Empiricism
The belief that knowledge or intelligence is created and acquired through experience or choice, the failed state of created knowledge or intelligence of "The First Spirit", and that sense experience is the ultimate source of all knowledge. Empiricism is associated with the idea that the human mind is "blank" at birth and develops its thoughts through experience. The image of the pattern of infallibility becomes the pattern of the selected "spirit" and is the Will of the Selected spirit and manifests life with respect to the intelligence's ability to manifest infallibly, forever without failure. In logic, the undefiled state of intelligence is in the pattern consisting of "Not" failure. Removed in the real intelligence is the pattern consisting of no chance of defilement and internal temptations to fail will not be included becoming the pattern of infallibility. The real intelligence will never fail in eternity and consists of One Unfailing Will, or pattern of behavior as intrinsically infallible. We become as one in being in the unfailing will of creation re-imaged, logically and through the Faith of Abraham, the Father of Faith and Isaac, logically, the "first" Priest and Sacrifice, fulfilled by The Christ, we become reborn and saved.
Was that a reaction to, "Empiricism is the ONLY path to knowledge about reality"?
The empiricist is also a rationalist and respects pure reason (mathematics, philosophy) divorced from experience as a source of knowledge, but not knowledge of external reality until it is applied to observation/experience.
Perception is not the only source of knowledge.
"Knowledge can be produced in many ways. The main source of empirical knowledge is perception, which involves the usage of the senses to learn about the external world. Introspection allows people to learn about their internal mental states and processes. Other sources of knowledge include memory, rational intuition, inference, and testimony." (Wiki)
I'll describe my understanding of these matters. It's a bit long, but I think a helpful framework for understanding what empiricism and knowledge are:
Perception isn't limited to the external senses. That's used to determine how the world outside of ourselves works. This includes both what is considered objective knowledge such as whether it's raining or sunny out, but also subjective knowledge, such as what one considers delicious or beautiful. This is still empirical knowledge even if it doesn't apply to everybody or even anybody else. I like strawberries but not Brussels sprouts. I discovered these facts empirically - by tasting them and evaluating the experience. These are facts for me for as long as my tastes don't change. The conclusions that I like this and not that are inductions drawn from experience, and they are predictable and reproducible.
We also have internal senses. Think of the body as organized into an outer body comprising skin, muscle, bone, tendons and ligaments, the so-called somatic body, which gives the body its form, protects the inner organs, and allows for movement. Our somatic sensory system tells us about the position of our limbs and any movement. We can learn how to use the body to accomplish assorted goals such as playing a music instrument, which is done empirically (through experience) and leads to the acquisition of a different kind of knowledge, a new assortment of inductions and reproducible outcomes.
We also have the visceral body, which is the collection of soft organs such as the heart, lungs, liver, and kidneys. Sensors in these lead reveal problems in those organs such as angina and heartburn. Once again, we can learn from experience that peppermint, for example, causes heartburn. Once again, this empirically discovered and is also a source of subjective knowledge about ourselves.
Then there are the chemosensors, which surveil the body chemistry and tell us for example when we're thirsty (dry/hyperosmolar blood) or short of breath (hypoxemia/low blood oxygen content).
The nervous system is the final compartment. We don't generally receive messages that arise in the spinal cord or peripheral nervous system - it generally is receiving messages from the somatic and visceral body and transmitting them to the brain or directly to muscle as with a patellar reflex (knee jerk) - but when we do experience the nerves without them being stimulated by other tissues, it is generally pathological, such as pain and tingling in the feet from peripheral neuropathy.
And finally, we can consider the brain itself, which is relevant when discussing "memory, rational intuition, inference, and testimony." Intuition shouldn't be called rational, and it isn't knowledge about external reality - just about oneself, like a god intuition or even the irresistible intuition that there exists a reality outside of consciousness. It's intuition when we say we know or think we know but can't say how we know or demonstrate that we are correct.
Moral knowledge is also intuitive. We can only say what we consider right and wrong according to our conscience or lack thereof. We can also acquire subjective but reproducible knowledge about what pleases our conscience and what offends it - what leads to feeling good or bad about one's choices.
We can also acquire knowledge empirically about our memories and our reasoning faculties such as how reliable those memories are and how successful our reasoning processes are. Inference is reasoning, which can be applied to evidence or can be pure reason as with
if this then that or mathematics.
I don't know how testimony got into that list, but testimony is acquired through the external senses and its meaning and validity evaluated using reason and memory.
Anyway, altogether, we can acquire knowledge empirically not just about the outside world - so-called objective reality - but also about how our bodies and minds function.
I call an idea knowledge when it accurately anticipates outcomes. Other ideas include intuitions and ideas accepted by faith. These are not knowledge about our common reality or our personal reality by that definition, although many call their nonempirically acquired and untested (and possibly untestable) beliefs knowledge.
You've seen them on RF and elsewhere. They "know" they're going to heaven, or they call empiricists who reject their nonempirical beliefs acquired by special, nonempirical ways of "knowing" guilty of scientism, or the excessive trust in empiricism, when what it is actually is distrust of the results of these special ways of "knowing."
And that's where this subthread began:
He: "you 100% believe that physical evidence is the only pathway to discerning truth."
Me: "Empiricism is the ONLY path to knowledge about reality. I know that you reject that, but you can't successfully rebut it, which is always the case with correct statements."
Something is truth or knowledge or fact or correct just because it is fervently believed. One has to demonstrate empirically that the idea allows one to successfully predict outcomes. Whatever can do that can be called truth, fact, correct, or knowledge, and nothing that can't should be called any of those.