How does one gain objective knowledge?

How does one gain objective knowledge? Is it from other people?

It’s pouring down with rain at the moment. That’s an objective fact so I now have knowledge of the current weather conditions in Bondi and no-one needed to tell me.

This could turn out to be a very profound, subtle question. What do you mean by “objective knowledge”? Does the witness of the senses count as such?

Knowledge of an external reality outside of our own subjective mind. An example would be the meaning of words.

Does it matter if most Americans cannot seem to identify even the most basic objective facts?

But even the meanings of many words change and shift over mere generations…

Aquinas presents a good discussion HERE.

I would say we know that a truth is true, objectively, when it is received from Truth Himself. The infused Gifts of the Spirit (Isa 11:23) given at Baptism, in potency, made come-alive by actual grace, communicate with confidence the truth of matters in independence of the senses and of other human testimonies.

Knowledge of an external reality outside of our own subjective mind. An example would be the meaning of words.

Now these are fun questions. What is knowledge, what does it mean to have it, and how do we have it? How is it possible for us to have any real knowledge of other things?

I have more to say on the topic, I just need time and opportunity.

1 Like

The certainty of received knowledge as objective knowledge depends upon its source. If the source is subjective then the objectivity of what is received remains uncertain for we cannot know what admixture of subjective bias has been melded into objective truth.

Science is a construct of the mind which attempts to find order in the chaos of observed phenomena in order to predict some future phenomena. The subjective mind, the observer and predictor, may be regarded as regaining from nature that which the same mind has put into nature.

While there is an objective truth about nature, we can never be certain that the subjective mind has not unknowingly tainted that truth. The scientists follow footprints in the sand of phenomena and come to the discovery that these are their own footprints.

Only revealed knowledge from Truth itself, mystic knowledge, can have the certainty of objective truth.

1 Like

OK… so “sense perception” doesn’t count, since it’s mediated / processed by our “own subjective minds”.

This is Kant’s problem, too: he claims that we absolutely cannot experience things-in-themselves.

Due to time, mood, and tiredness I’m not sure I can provide my best explanation now (in either thoroughness or readability), but if I don’t do it now I’m not sure when I’ll have the opportunity. I’ll also add that this is still an area of study I’m not 100% comfortable with. I feel okay discussing it but take it with a few grains of salt as to whether I’m explaining it incredibly accurately.

St. Thomas Aquinas believed that human beings were capable of real knowledge of other beings. He also agreed with Aristotle that “nothing is in the intellect that was not first in the senses.” In St. Thomas’ writings, and in commentaries on his writings by John of St. Thomas and Cajetan (or by reading a handy secondary source which presents all this in English), we can understand the discursive process by which St. Thomas believes we can come to real knowledge from sense data.

Before I continue, I’ll just state that St. Thomas did believe we can reflect on our own knowledge, and that we can make rational arguments from what we know to other knowledge. But these posts will focus on how we gain knowledge of other things by the senses.

Human beings are acted upon. Things touch our skin, light hits our retinas, molecules bind with our taste buds and olfactory glands, vibrations are created in our inner ear. These are our senses and the raw sense data we obtain. These in themselves provide immediate sense knowledge (distinct from conceptual knowledge) of there being an other. They are concrete and objective. They are not in their nature deceptive, but we can be deceived by some accidental impediment to them.

Continued in next post.

Continued from previous post.

We have four inner senses according to St. Thomas. There is the “common sense,” which is our body’s ability to to take the raw sense data and present it as a unified sense experience. The common sense is always in the present. It only presents what’s currently being received by the raw senses. Our inner senses also include the powers which St. Thomas referred to as “phantasy.” These are the powers of memory, estimation, and imagination. These powers are “phantasy” in that they can present or re-present what is not currently being received by the raw senses. The imagination is considered to be most properly called phantasy as by it we can re-present mental visions, sounds, taste, smells, and touch. I should clarify that in common use the word “imagination” is used broadly to refer to a person’s creative ability. The term imagination in this discussion is more precise to what I described before.

The internal senses present phantasms of the external object. Phantasms are sort of our perceptual experience, and are also what comes to my mind when asked to “picture yourself on a tropical island”. Phantasms are always under the “conditions of matter”. That is, they are not material in themselves, but when perceiving or picturing (or imagining a sound, touch, taste, or smell) we do so with things like size, color, texture, pitch, the conditions we find naturally existing objects to have.

All of the above are sensitive powers. But phantasms are not knowledge and they’re not concepts. They are all particularized by conditions of matter. How do we move from that to understanding universal concepts? There is an active power by which a person, taking the phantasm, abstracts the universal form of the thing presented from the conditions of matter. We can understand something apart from a particular image of it, and in a universal sense applying to all particulars that have the form. This form is what actualizes the potential of the impressed intellect. The impressed intellect, as I understand it, is a sort of reservoir of intelligible forms (reservoir being my own word). This isn’t the step by which we know the object as other, that is next, but that we must retain the forms is necessary if we are to be able to call them back later when the object is not around.

Continued in next post

Continued from previous post

The final step is when impressed form actualizes the possible intellect such that the form is expressed. The expressed form is the concept, or similitude or image of the external object. The form which has a natural existence in the other object has an intelligible or psychic existence in the knower. I must reiterate that I speak of the same form existing in different modes; I don’t speak of a phantasm under the conditions of matter, but of form abstracted from such. The knower has the same form as the object (not as the form of his substance, but intellectually) and is in that way one with the object. The concept, however, is not the object of knowledge. The concept is the medium in which the knower knows the external object. It intelligibly contains the object. The concept is not the object of knowledge, but the means by which the knower obtains the object of knowledge which is other. It is important to emphasize the difference here with Descartes, the Rationalists, and the Idealists, who all profess that the concept is the object of knowledge.

This is a very, very, very hurried presentation. Perhaps I can help elaborate if there are any questions. A few points I’ll throw in here.

  • It’s important to understand that the way in which the sense data and phantasms act as deputies of the other object.
  • Raw sense data is not willy-nilly, the sense data is determined by the external object.
  • The phantasms are determined by the sense data and external object.
  • The active intellect, again, isn’t willy-nilly, but is determined by the phantasm which is a deputy of the other object. As a musician is determined to play violin music when using a violin as an instrument, the phantasm is an instrument of the external object which determines the active intellect.
  • Hylemorphic dualism is actually key to understanding this whole thing. Certainly the physical object being known isn’t changed by being known, its matter doesn’t enter the knower, nothing material in the knower conforms to the known object in any material way. The knower is united by form, and this is necessarily immaterial, which I may justify more later. And while I can imagine some sensists objecting I’d like to see some alternative models presented which show an understanding of the issue. I have written something else on hylemorphism which I may cannibalize later…

Note I don’t claim to have justified everything or that everything is self-evident. It’s definitely not self-evident. My intent was to lay out a sketch. As I said before, I may have opportunities to try to hash this out to questions or objections. Maybe I can do this topic some justice at some point.

Perhaps the question that first must be be answered is: Can one gain objective knowledge?

There are those ideas like Solipsism that say no, and Kant argued that it is impossible to directly experience the fullness of reality.

What does a tree look like in your minds eye if one is born blind? How does one create that image?

The problem, as it were, is that the “concept-of-tree” is not a tree itself. Can you objectively know the tree in your front yard if you’ve never experienced it?

Let’s take it a step further: can you objectively know the tree in your front yard if you’ve only experienced it subjectively – through your personal senses and your personal intellectual processing of those sense experiences? Wouldn’t that imply that you’ve only experienced it subjectively, through the mediation of your personal faculties?

1 Like

Each person creates knowledge through interacting with reality.

What do you mean by “objective” ?

I think this question is imprecise as-is. Terms need to be defined.

E.g. the only context off the top of my head where we can clearly talk about ‘objectively-known’ truth is in a logically deductive argument. That is, one which has the algebraical form of:

if A = B
and B = C
then A = C

It’s just objectively true that the conclusion (third line) follows from the two premises above (first and second lines). BUT all propositions that can fit into this format must have the premises proven before the conclusion is proven. i.e. has it been conclusively proven that A does equal B? and has it been conclusively proven that B does equal C? Only then can you conclusively state that A = C.

This is just in terms of what we can objectively ‘know’ here on earth, of course, where sensory perception and cognitive function is fallible and prone to error. God is, of course, capable of bypassing our usual (mediated) form of accumulating knowledge (which is often not quite as firmly ‘knowledge’ as we may think it is), to grant us revelation of some truth that we then do objectively know. Trouble with that kind of non-mediated revelatory gain of objective truth, is we can’t turn around and mediate it to others. It has to be specially granted from God to each person.

The traditional discussion is in regards to whether humans can have real knowledge of things as they are. That doesn’t mean it has to be complete knowledge.

DISCLAIMER: The views and opinions expressed in these forums do not necessarily reflect those of Catholic Answers. For official apologetics resources please visit