What is a fact? 

A fact is something made or done, which has a clear objective status. There are two basic types of facts: Things and Events. A thing is an existing entity (e.g. The White House) established by direct or indirect evidence. An event is made up of things (e.g. The assassination of Abraham Lincoln) established relying on other facts. Things and events are objective facts, but there are also subjective facts, which are limited to the subject experiencing them, such as a headache, which occurs in the objective physical world, but its experience is limited to the subject. In establishing the factualness of events experienced indirectly, we must exercise the same care as when we attempt to establish the factualness of things by indirect evidence. 

The objects and origins of ideas

An idea is the subjective evocation of an objective fact. Ideas in the mind are ultimately traceable to a thing existing in the world, independently of the mind. Clear ideas are ideas which faithfully reflect the objective order from which they derive. Unclear ideas, conversely, give a distorted representation of the objective world. It is wrong to suppose that because we know things in the world only through ideas, it is only our ideas which we really know. Our ideas are the means, not the ends, of our knowledge. They link us to the world. If they are clear ideas, the links are strong. The most efficient way to clarify our ideas is to look through them to the objects they represent. Our ideas owe their existence, ultimately to things outside and independent of the mind, to which they refer: objective facts. Our ideas are clear only to the extent that they keep constant tabs on the things to which they refer. I establish a fact if I successfully ascertain that there is, for a particular idea I have in mind, a corresponding reality external to my mind.

The components of human knowledge 

There are three basic components to human knowledge. An object, that is, an objective fact (e.g. a cat); A subject, that is, the idea of a the fact  (e.g. the idea of a cat); and Language, that is, the word we apply to the idea (e.g. in English "cat"). How do ideas relate to the objective world, for the relation is not always simple? Simple ideas: one-to-one correspondence between idea and thing. Complex ideas: no simple one-to-one correspondence between idea and thing. The correspondence is one to many. (e.g. "democracy" involves persons, events, constitutions, institutions, etc.). To prevent an idea from being the product of pure subjectivism, we must continuously touch base with those many facts in the objective world from which the idea is born.

What constitutes effective communications?

Matching words to ideas is the first step in communication. The next step is putting ideas together to form coherent statements.

The words we speak refer to the ideas we are deal with, but they say nothing about what we intend to do with those ideas. The words we speak say the idea, we are not saying anything about the idea.

We say something about ideas when we put them together to form statements that can be responded to affirmatively or negatively. 

If someone says "dog," this is neither true nor false; but if someone says "the dog is in the garage" then we can refer to the objective world and say whether this statement is true or false. Words are the building blocks of language, but logic starts with statements, for it is only at the level of the statement that truth or falsity applies, and logic is concerned with distinguishing between what is true or false.

It is impossible to have a clear communication without clear thinking. However, clear ideas do not guarantee clear communication.

Guidelines for effective communication

Don't assume your audience understands your meaning if you don't make it explicit. Speak in complete sentences. Don't treat evaluative statements as if they were statements of objective facts. Evaluative statements do not lend themselves to a simple true-or-false response. E.g. "This building is on the corner of Main street" is a statement of objective fact. "This building is ugly" is an evaluative statement, as such it combines both subjective and objective elements. We must not invite unwarranted responses to statements, which is just what we do when we attempt to pass off an evaluative statement as if it were a statement of objective fact. True statements of objective fact are not open to argument; evaluative statements are. If one wants an evaluative statement to be accepted, one must argue for it. Avoid double negatives 

E.g. "It is not unlikely that she would be welcome;" say instead "she would be welcome". Gear your language to your audience. Avoid evasive language. The user shapes language, but language shapes the user as well. Evasive language can distort the reality of both the audience and the user – user may come to believe their own distorted reality represented by inadequate language. 

Truth

The whole purpose of logic is to arrive at the truth of things. This is often a painful task. But not to pursue truth would be absurd, since it is the only thing that gives meaning to all our endeavors. It would be equally absurd to believe that truth can never be attained for that would render our activities purposeless.

Truth has two basic forms: Ontological truth, which is the truth of being or existence; something is said to be ontologically true if it exists; and Logical truth. Logical truth is simply the truth of statements. What a true statement does is declare, through the medium of language, a correspondence between ideas in the mind (subjective facts) and real states of affairs in the world (objective facts). Establishing the truth is a matter of bringing together into harmonious juxtaposition the subjective and the objective. What determines the truth or falsity of a statement is what actually exists in the real world. Logical truth, in other words, is founded upon ontological truth. 

Lying is more a psychological problem than a logical one: when one lies, one know that A is B but consciously claims that A is not B. 

Correspondance Theory of Truth and Coherence Theory of Truth 

The coherence theory of truth views logical truth as a matter of correspondence between the content of a statement (which reflect the ideas of the subject - the person making the statement) and objective facts. The coherence theory of truth maintains that any given statement is true if it harmoniously fits into (is coherent with) an already established theory or system of thought. But the coherence theory of truth, if responsibly applied, depends upon the correspondence theory of truth, which remains foundational. 

We should be aware that the coherence theory of truth can be seriously abused, which would be the case if a statement is judged to be true merely by virtue of the fact that it fits into an established theory or system of thought that itself does not correspond with reality, or does so only questionably. For example, if Marxist economic theory can be  shown to be dubious, then the claim that a certain statement about economic matters is true because it is consonant with that theory is likely dubious.