What is Logic?
A Street-Preacher does not need to be on his podium for long before an atheist will suggest that religious belief is irrational, mystical, a belief in the unknown, or just plain fantasy. “It is not logical,” it will be asserted without argument, “to believe in the existence of God.”
How, then should the Street-Preacher deal with the question of logic? Is the atheist on strong grounds when he asserts biblical belief is ‘illogical’? What, however, is logic?
Logic has been described as the science of necessary inference. Logic is the use of propositions in a particular manner. Propositions are statements that are either true or false. Syllogisms, the use of propositional statements, on the other hand, are either valid or invalid, sound or unsound. An argument may be logically valid, but unsound because of the nature of one of the premises. A sound argument is one that is both valid and the premises are true. It is the combination of these concepts that allows logic and logical arguments to take place.
To address the question “What is logic?”, however, the Street-Preacher will find it necessary to have an argument not so much about logic, but about the philosophy of logic. What is logic? What determines whether certain propositions are logical or not? What determines that an inference is necessary? And in order to find a philosophy of logic, the Street-Preacher need search no further than his doctrine of God.
Logic is the claim that certain ‘facts’ stated as propositions fit together in some kind of relationship and the correct relationship is “logical” while the incorrect relationship is a ‘fallacy’.
All wisdom and knowledge find their resting place in the concept of God as the absolutely self-attesting, or self-determinative, God. To understand what this means, consider the competing worldviews of atheism and biblical theism. The atheist is adamant that the ‘facts’ of the universe came into existence by chance. Having denied a Creator who is a person, the atheist is left with no intelligent designer behind the ‘facts’ that came into existence. All facts to him are impersonal. Their existence and their place in the cosmos is the result of randomness.
Descartes’ Philosophical Revolution
In the history of Christian philosophy, Anselm stands as one of the key figures. His idea that one must trust God (i.e. believe) in order to understood, was a high point in the Middle Ages.
But in the 16th century, Rene Descartes turned the world upside down. In trying to establish what he thought would be an indubitable starting point for human thought, his answer was the opposite to that of St. Anselm.
Cogito ergo sum—I think, therefore I am—placed the human mind as the unquestionable starting point in all human predication. Now, God and everything else would have to be proven by the mind of man that was now unlinked from everything. The mind of man was now autonomous.
Now the problem with this statement seems hidden from Descartes. And the problem is this. His idea of cogito ergo sum is not logical. It assumes what it is supposed to prove. Consider this syllogism:
P1. I think
P2. In order to think I must exist
C. Therefore I exist.
The problem is that the conclusion ‘I exist’ is assumed in the first premise: ‘I think.’ The moment the ‘I’ word is used, it assumes existence. In order to not beg the question, therefore, the first premise ought to be: ‘There is thinking going on,’ and you cannot get from there to ‘I exist.’ So, you can’t know that ‘you think’ because you have not justified that you exist. Consider the revised syllogism:
If you want to know what’s wrong in the world today, it’s tempting to answer that with a single issue. In reality, there are many things that contribute to the state of the present world.
Not least of these, however, is critical thinking or, rather, the lack of it.
There are some who will make all kinds of excuses why logical thinking should be abandoned or denied. Some do it on the basis that this is “Greek” thinking and we should be “Hebrew” in our thinking, the implication being that “Hebrew” thinking somehow does not demand the same kind of logic. This view of Greek and Hebrew, however, has the wrong point in mind, for this is not the real distinction between Greek and Hebrew thought. It is the outcome of our logical thinking that illustrates our presuppositions, and these are either biblical or they are not.
Statistics are a highly logical and precise way of stating half-truths inaccurately.
The place of mathematics and statistics in modern society is very much the result of a philosophy that identifies the mind of man as the arbiter of what is true. The sciences are, apparently, our only true guide to life. This results in a biased dependence upon mathematics in particular since it has a veneer of scientific accuracy. Science has become the tool for man to remake the world according to his own plans. And beware those who dare disagree with the scientists! It is this assumption of modern science, and its statistical manifestation in the field of economics, that needs to be challenged.
Earlier this century two schools of economic thought appeared which have relied on mathematics to substantiate their basic ideas. Neither of them were distinctively Christian in origin, yet both have been defended in the name of Christianity in later years. One school had its origin in a British engineer, Major C.H. Douglas, and is popularly known as Social Credit. The other received its basic popularity from John Maynard Keynes, a person just as famous, maybe even more famous, for his perverted lifestyle than for his economic theories. Both schools of thought have relied on one particular premise from which they built their respective ideas. Both Major Douglas and Keynes believed that the economic problem was not enough money. However, they disagree in the manner in which this basic premise is worked out and integrated into the respective theories, especially the solutions offered as a remedy to the perceived problem. They argue their views strongly, suggesting there is statistical evidence that “proves” their theory.
Neither Keynes nor Douglas, however, originated the underlying philosophy of their views. That privilege remains with Pierre-Joseph Proudhon whose dictum — property is theft — was to rattle the cage of every nation around the world. It also forms the basis for the anti-capitalist mentality of our age. But the statement “Property is theft” provided the backdrop for Proudhon and his disciples, Keynes and Douglas, to state their case. Statistics of any kind really do not tell us anything about property rights.
You see the words in the headline above and you wonder what on earth could be the most obstinate adversary to thinking. The phrase originated with Martin Heidegger, according to William Barrett, who quoted it. It was in italics. It must be important.
Here’s the complete sentence so you get the context:
Thinking only begins at the point where we have come to know that Reason, glorified for centuries, is the most obstinate adversary of thinking.”
You could be forgiven for thinking that Heidegger might have been speaking about the philosophic struggle between Rationalism and Empiricism. This is the battle for knowledge: do we gain knowledge empirically, by the senses, or by thought, making rational conclusions? Since Kant there has not been an answer to that question outside of the Biblical framework of thinking, and more particularly the Calvinistic framework of Christianity. A good part of the reason for this is the Reformed emphasis on a rigorous application of the mind and the senses to what Scripture reveals.
- William Barret, Irrational Man (New York: Doubleday Anchor,  1962), p. 206.↵back
“Thus the first step that the current scientific method is asking you to take is to assume that the facts that you meet are brute facts. I say you are asked to assume the existence of brute facts. If you did not assume this you could not be neutral with respect to various interpretations given of the facts. If God exists there are no brute facts; if God exists our study of facts must be the effort to know them as God wants them to be known by us. We must then seek to think God’s thoughts after him. To assume that there are brute facts is therefore to assume that God does not exist.”
Cornelius Van Til, “A Calvin University,” in The Banner, November, 1939.
Philosopher Gordon H. Clark says in one of his lectures: “There are complications. And if you want to learn the subject you have to learn the complications, that’s what the subject is. And if you don’t want to learn the subject, well go out and play golf. I don’t know why anyone would want to do so, but apparently some do.” Too many critics of Van Til have failed to learn the complications, and thus don’t know the subject matter.
“Most heresies begin with a partial use of Scripture and end with an alien faith.” — R.J. Rushdoony
Myth — a person or thing having only an imaginary or unverifiable existence. — Merriam-Webster Dictionary.
1. The Problem Defined
2. Mirror Theology
3. From the Mountain Top
4. The Meaning of Sovereignty
5. Anthropomorphism: Smoke and Mirrors
6. Whatever Happened to Sin?
7. The Myth of Libertarian Free Will
8. Is God Irresponsible?
9. God Overboard
When Marcus Tullius Cicero introduced philosophy into the Roman Empire, he helped set the stage for one of the most volatile debates as Christianity spread throughout the Empire. His influence on Renaissance thinkers ensured the clash of ideas that eventuated between Erasmus and Martin Luther. Cicero was a statesman, lawyer, politician, and a gifted orator. But he was more than a famous citizen and politician: he was a philosopher in the Greek tradition, an ardent defender of the freedom of the will, what is called “libertarian free will.”
Libertarian free will is the idea that in order for man to have choice and true contingency it cannot be as Luther argued, and Augustine before him, the free will of a created being, as distinct from the free will of an uncreated being. In order to qualify for the name, some people argue that man’s free will must be identical to God’s free will. They may not phrase it exactly like this, but this is what the demand for libertarian free will requires. What they believe is that in order for man to be “free” he must be beyond the control of God.
In order to qualify for the name, some people argue that man’s free will must be identical to God’s free will.
The Problem Defined
Defenders of libertarian free fall into a pattern. They deny God’s infallibility, they renounce the traditional views of his omniscience and his immutability, they assert God is everlasting but he is not timelessly eternal, and, naturally, they disavow any concept of the eternal decrees. Any God who knows the future infallibly destroys human choice, they say. If God knows now (at this moment) that you are going to get run over by an 18-wheeler tomorrow afternoon at 4:45 pm, then there is nothing you can do to prevent that. You cannot choose to take another route and thereby avoid the collision with the trailer.
How does an atheist know when he is speaking the truth?
When an atheist confronts the Street-Preacher the discussion must eventually turn to the question of epistemology: how you know, and how you know that you know what you claim to know.
The initial problem the Street-Preacher will encounter with the atheist is either ignorance of the meaning of the word epistemology, or else he will meet an atheist who has been in philosophy classes and will most likely tell the preacher that a discussion on epistemology is a waste of time.
In order to move the discussion in the right direction, however, the Street-Preacher just needs to keep asking one question, “How do you know that?” And then wait for a reply.
If the Street-Preacher is fortunate enough to get a reply, he will rarely get an answer to this question. He will be given words that cannot be construed as a reply to the question. And that’s because the atheist doesn’t understand what is being asked.
It is important, then, to make sure the atheist understands and comprehends that the Street-Preacher is not asking what the atheist might know, but how he knows what he claims to know. For example, an atheist might reply that he knows that 1+1=2, and when asked how he knows it, he might reply that this is a ‘verifiable’ proposition. If that answer is given, however, the Street-Preacher needs to recognize that he has not been given an answer to his question. What he has been told is the process which is open to the atheist that the atheist alleges answers the question.
But as soon as the Street-Preacher asks yet again, “how do you know that ‘verifiable’ identifies how a person knows something,” you can see that the atheist’s answer does not address the how question at all. Often the atheist will come up with yet another response, and suggest he ‘knows’ because the issue is agreed to by 93% of current scientists. And so the atheist needs to be asked again, ‘how do you know that 93% of the scientists are correct?’ Or, ‘how do you that 93% is the cut-off point rather than 95% or even 99.9%?’
Here is a very succinct survey of modern philosophy from Rene Descartes to Immanuel Kant. It’s a one-of-a-kind explanation of how our world has gotten itself into a mess. It takes about 15 minutes.
If you like this excerpt, then you can hear the full one hour lecture here.
This lecture is taken from a series of 10 lectures entitled “Epistemology” by Dr. R.J. Rushdoony. You can find all of them here.