Archive for the ‘Logical fallacies’ Category

Freud, antitheism and the genetic fallacy

freud2When Freud’s writings touch upon the issue of religion and the divine, there lies a fascinating intersection of modern ideas. While Charles Darwin had provided the scientific theory of the mechanistic origin of man from simpler life, Freud’s great contribution to the Enlightenment secular edifice was to psychologise man’s religious activities.

If one wishes to form a true estimate of the full grandeur of religion, one must keep in mind what it undertakes to do for men. It gives them information about the source and origin of the universe, it assures them of protection and final happiness amid the changing vicissitudes of life, and it guides their thoughts and motions by means of precepts which are backed by the whole force of its authority.

– Sigmund Freud, New Introductory Lectures on Psychoanalysis

Per Freud religion exists in order to placate man’s need for wish fulfillment. Specifically, religion exists because of man’s fears regarding the indifference and power of the natural world and because of its sometimes usefulness in promoting social cohesion and order. Religion is for Freud the attempt of an infantile man to use illusion to create a better world. In Freud’s theory one also finds the progressive anthropology common in the writings of thinkers such as Rousseau and Comte, where it is postulated that the primitive ideas of religion will eventually be shed by a new type of scientific man.

But is what Freud has to offer a refutation of religious ideas or simply a type of historical classification? In this regard Freud seems to take a similar approach to Nietzsche.

Historical refutation as the definitive refutation. — In former times, one sought to prove that there is no God — today one indicates how the belief that there is a God could arise and how this belief acquired its weight and importance:  a counter-proof that there is no God thereby becomes superfluous. — When in former times one had refuted the ‘proofs of the existence of God’ put forward, there always remained the doubt whether better proofs might not be adduced than those just refuted:  in those days atheists did not know how to make a clean sweep.

-Friedrich Nietzsche (1844-1900), Daybreak:  Thoughts on the Prejudices of Morality, Book I, sec. 95

The genetic fallacy is a type of logical fallacy whereby a conclusion is proposed based upon some fact regarding the origins of something. It is a fallacy because the conclusion is unsupported by irrelevant facts regarding the subjects origin. Freud fails to take into account that the truth (or falsity) of his psychological theory regarding the origins of religion are consistent both with the existence and non-existence of the divine.

Formal and informal fallacies

circular-reasoning-works-becauseAssessing the validity of an argument is an important skill, and not only for the philosopher. An argument can be called into dispute in two separate ways: either through the accusation of a formal or informal fallacy. A formal fallacy involves an error in the form or structure of an argument, whereas an informal fallacy involves an error in the premises.

For a first example, take modus tollens:

If P, then Q. (It it is sunny, we will go outside).

Not Q. (It is not sunny).

Therefore not P. (Therefore, we will not go outside).

The above is a formally valid argument – in other words, if the premises are true then the conclusion must be also true. However, whether the premises are in fact correct is a separate issue. There are a whole host of informal fallacies (such as equivocation, begging the question, or ad hominem) that may ultimately render the conclusion false or unpersuasive.

For a second example, take the non-sequitur argument denying the antecedent:

1) If I am a cat, I am a mammal. (Antecedent = being a cat)

2) I am not a cat. (Denial of antecedent)

3) Therefore, I am not a mammal.

The above is a formally fallacious argument. Note that even though the premises and conclusion may well be true (i.e. no informal fallacies), the syllogistic structure of the argument causes the conclusion to be in no way supported by the premises.



Auguste Comte and positivism

Auguste_Comte2Auguste Comte (1798 – 1857) was a French modern philosopher. Comte was born towards the end of the French Revolution, and the upheaval of that time would become a large influence on his work. His solution to the lethargy of post-revolutionary France was the development of his social theory of the “Religion of Humanity”, which would eventually be succeeded by the post-Enlightenment movement of secular humanism.

Like Hegel and Rousseau, Comte took a tripartite view of the evolution of society. Comte called the first stage of this development the theological stage. This era was marked by three sub-stages of fetishism, polytheism and monotheism. The hallmark of the theological stage is the sluggish progress of a man that is largely shaped by his unquestioning acceptance of the crude beliefs of his ancestors.

The second stage Comte named the metaphysical stage. By metaphysics, Comte is not referring to the philosophical systems of say Plato or Aquinas, but rather to  France prior the revolution when thinkers like Rousseau and Voltaire began to question the dogmas of religion and the monarchy.

Comte’s third epoch was the scientific society. In this final stage, there was no need for appeals to either religion or unprovable metaphysical assertions. In their place, man was to apply the scientific method to his problems in order to reach an informed solution.

To support his utopian scientific society, Comte invented the empirical epistemology usually called positivism, evidentialism or verificationism. According to Comte, the only kind of fact is scientific fact – those that are fully investigable by the modern scientific method and borne out by empirical evidence. In this way, Comte can be considered to have finished the work that Voltaire had started in his criticism of metaphysics.

Comte’s thought was popular in the 19th century and was largely influtential on thinkers such as Marx, Nietzsche and Mill, but began to lose favour when the obvious criticism of positivism as self-vitiating arose. Positivism enjoyed a brief rebirth in the early 21st century in the work of science popularisers such as Richard Dawkins.


Modus ponens and modus tollens

modus-tollensPreviously, I have examined a type of fallacious argument called non-sequitur. While non-sequitur is fallacious, its deceptive nature comes from the fact that it resembles a perfectly valid type of argument called modus tollens and modus ponens.

Modus ponens is latin for “the way that affirms by affirming”. It can be summarised as follows, with an example in brackets:

If P, then Q. (If it is raining, then we will stay inside).

P. (It is raining).

Therefore Q. (We will stay inside).

Modus tollens is latin for “the way that denies by denying”. It can be summarised as follows, with an example in brackets:

If P, then Q. (It it is sunny, we will go outside).

Not Q. (It is not sunny).

Therefore not P. (Therefore, we will not go outside).

It is important to note that while an argument is logically sound provided it follows the formula of modus tollens or modus pollens, the validity of the premises may still be called into question.

Ad hominem: fallacious and legitimate

Leo blog : The Heartland Institute conference billboard in Chicago

Let’s just say I have a conversation with my very good friend about the effects global warming could have on the welfare of people living on near-sea level pacific islands. And my friend replies, “Of course you are concerned. You believe in that climate change garbage because you are a raging leftie!”

An ad hominem argument (where ad hominem is latin for “to the man”) is a type of fallacious reasoning whereby an argument is rejected based upon some irrelevant fact about the author or the argument’s proponent. In the example above, the irrelevant fact would be my supposed left-leaning tendencies. In the picture accompanying this post, the irrelevant fact is that the Unabomber (considered a deranged person) also believes in global warming.

However, not every ad hominem is fallacious. Consider if I offered my friend above the following rejoinder. “I don’t think global warming is real only because I am a leftie. I think it’s real because people like Tim Flannery are experts on the matter and their advice is reliable.” Now following this second line of argument, which rests on the credibility of Tim Flannery, it would certainly not be fallacious for my friend to attack Tim Flannery’s credentials in regards to climate science and his track record of climate predictions.

A related fallacy is called the tu quoque (latin for “you too”). Let’s say my friend finishes with this, “You think climate change is going to harm people but everyday you drive your car to work.” Notice that the implication here is that my personal hypocrisy in some way invalidates my argument (i.e. you too!). A well-known historical example of the tu quoque is the famous Russian response to America’s criticism of their human rights record in the 20th century, which was “And you are lynching negroes”.

The reification fallacy

Gestalt-1-reificationAbstract concepts or ideas are of enormous value. When we consider some particular aspect of a real concrete object while disregarding its other aspects we are engaging in abstraction. For example, imagine a wooden table 3 x 3 x 3 metres. When I think of the 3 x 3 metre square form of the table while ignoring its wooden matter, pine smell or chestnut colour I am creating an abstract from the table.

The philosophical problem of abstraction consists of  whether abstractions are real and what their ontology may be. It is an ancient problem. Consider the Pythagoreans, the pre-Socratic cult lead by Pythagoras that taught that the mot fundamental reality of the world was numbers. Thinking of the table before, a Pythagorean would answer that the 3 x 3 metre measurement of the table’s dimension was far more real than the wood and nails of which it is made. In this way, the Pythagoreans can be considered ultra-realists in regards to abstractions.

Pythagoreans (and following on Platonists) aside, commonly the reification of abstractions (reification means to “make real or concrete”) is considered a logical fallacy. But how regularly does this fallacy occur?

It is common in modern science – one may hear talk of “scientific laws” governing reality. Yet, are these laws real or are they mere abstractions of physical things and their dispositions? One may hear talk of natural selection as the cause of evolution, but is natural selection itself an abstract concept of the differential reproduction and survival of species (or furthermore is species itself an abstraction from a group of individuals)? Is the mathematical nature of modern physics an abstraction?

Much ado about nothing: Lawrence Krauss and ex nihilo, nihil fit


Ex nihilo, nihil fit is a latin maxim that can be loosely translated to “From nothing, nothing comes”. The first example of this thesis was argued by Parmenides and the idea was primary in Ancient Greek philosophy and has been ubiquitous throughout history. Ex nihilo, nihil fit is also essential to the success of cosmological arguments; take for example Aquinas’ fourth way:

Therefore, if everything is possible not to be, then at one time there could have been nothing in existence. Now if this were true, even now there would be nothing in existence, because that which does not exist only begins to exist by something already existing.

– Summa Theologicae

Lawrence Krauss is a professor of physics and author of a popular science book called A Universe From Nothing. To understand Krauss’ motivation for writing the book, it may help to know that Krauss is also an atheist and anti-theist proselytiser.

The contention of A Universe From Nothing is to scientifically demonstrate the falsehood of Ex nihilo, nihil fit. Krauss recently appeared on the ABC television show Q and A (here is a link to the show), where he provides the following summation of his argument (around 27 minutes in):

Empty space, which for many people is a good first example of nothing, is actually unstable.  Quantum mechanics will allow particles to suddenly pop out of nothing and it doesn’t violate any laws of physics.  Just the known laws of quantum mechanics and relativity can produce 400 billion galaxies each containing 100 billion stars and then beyond that it turns out when you apply quantum mechanics to gravity, space itself can arise from nothing, as can time.  It seems impossible but it’s completely possible and what is amazing to me is to be asked what would be the characteristics of a universe that came from nothing by laws of physics.  It would be precisely the characteristics of the universe we measure.

-Lawrence Krauss, Q and A

The problem with Krauss’ argument is obvious in a cringe-inducing fashion – Krauss is committing the fallacy of equivocation using the word nothing. According to Krauss nothing includes the laws of quantum mechanics, gravity and possibly others things – whereas for proponents of Ex nihilo, nihil fit nothing is quite simply nothing. Krauss ought to be congratuled for showing how something can come from almost-nothing, but he has fallen well short of demonstrating the falsity of Ex nihilo, nihil fit.

So Krauss’ argument is based on a jejune logical fallacy and ultimately fails – it couldn’t get much worse, right? Well, it does. Krauss’ position ultimately ends up being a criticism of the kind of materialism that he is advancing. If all being is physical and nothing (as Krauss uses the term) is not physical, then the nothing that Krauss describes (i.e. quantum mechanics, gravity etc.) must be non-being and not exist.