Keep it simple, silly!

We discovered the Law of Parsimony together and ventured further into Systematics (its a pity Systems Biology isn't getting introduced next sem..), so anyway, Divya, this one is for you.

And for all the others, yes, surprise surprise! I'm here to talk about philosophy, logic or the word that matters to you most  - study - yes, I'm here to talk about something related to studies. For a change..

William of Ockham

William of Ockham (or Occam, as I've always known..) was an English Franciscan philosopher - a friar - who is believed to have been born in Ockham, a small village in Surrey. He is considered to be one of the major figures of medieval thought and was at the centre of the major intellectual and political controversies of the 14th century. He is believed to have given a particular form of philosophy or principle which is widely used in logic/physics/theology and as we've seen, in biology/medicine too. It is often summarized as -
'Other things being equal, a simpler explanation is better than a more complex one.'
Before and after him, there have been similar proposals from established philosophers such as Aristotle and Ptolemy who had stated 'We considered it a good principle to explain a phenomenon by the simplest explanation.' and Nobel laureate Bertrand Russell has said something on the same lines. Even Ranbir Kapoor in his DOCOMO advertisements has propogated the KISS principle (articulated by Kelly Johnson, the acronym stands for 'Keep It Simple, Silly!') which is also a morphed version of Occam's razor.

Occam's Razor (Latin lex parsimoniae) is the Law of parsimony, economics or succintness and it urges one to select among competing hypotheses the one that makes the least assumptions and yet offers the simplest explanation of the effect.

Why razor? The German term, 'Okham's Messer' translates to 'Ockham's knife' refers to the 'shaving off' or 'cutting away' unnecessary assumptions and selecting the simplest explanation as long as it stands true.

Use in Science

For stating the obvious, Occam's razor is used as a heuristic or a commonsense rule intended to increase the probability of solving some problem or a general formulation that serves to guide an investigation. It is supposed to be an important rule in the formulation of the theory of special relativity by Albert Einstein, the development of quantum mechanics by Ludwig Boltzmann, Max Planck, Heisenberg, de Broglie (bas, naam hi kaafi hai, kyun..?). In chemistry, it is an important heuristic in developing a model of a chemical reaction mechanism.

But there are obvious failures of this principle. Though it acts as a good heuristic, it is however, not the most reliable option. It has been shown to fail as a criterion for selecting among selected established, published models.

Einstein had himself cautioned while he formulated Einstein's Constraint, 'Everything should be kept as simple as possible, but no simpler.' In my opinion, one can instead focus on the word 'Optimum' over 'Simple' right? What appears simple here, maybe it involves a complex by-pass in another parallel process, thus complicating the system on the whole.

In the scientific method, parsimony is an metaphysical or heuristic preference, not an irrefutable principle of logic and certainly not a scientific result! In another instance, classical physics is way simpler than more recent theories; nonetheless it cannot be preferred over them, because it is demonstratively wrong in certain aspect.


The philosophers of biology use Occam's razor in two contexts, both in evolutionary biology:

1) the units of Selection Controversy
2) and Systematics.

George C. Williams in his book Adaptation and Natural Selection (1966) argues that the best way to explain 'altruism' among animals is based on low level selection (i.e. individual) as opposed to high level group selection. Altruism, as you know, is the behavior that is beneficial to the group but not to the individual, and group selection is thought by some to be the evolutionary mechanism that selects for altruistic traits. Others state individual selection as the mechanism which explains altruism solely in terms of the behaviors of individual organisms acting in their own self interest without regard to the group.

The basis for Williams's contention is that of the two, individual selection is the more parsimonious theory. In doing so he is invoking a variant of Occam's razor known as Lloyd Morgan's Canon: 'In no case is an animal activity to be interpreted in terms of higher psychological processes, if it can be fairly interpreted in terms of processes which stand lower in the scale of psychological evolution and development.'

However, more recent biological analyses, such as Richard Dawkins's The Selfish Gene (the book I had told you about, alongside Autobiography of a Species in 23 Chapters), have contended that Williams's view is not the simplest and most basic. Dawkins argues the way evolution works is that the genes that are propagated in most copies will end up determining the development of that particular species, i.e., natural selection turns out to select specific genes, and this is really the fundamental underlying principle, that automatically gives individual and group selection as emergent features of evolution.

Zoology provides excellent examples. Certain animals including SOME humans, when threatened by wolves, will form a circle with the males on the outside and the females and young on the inside. This as an example of a behavior by the males that seems to be altruistic. The behavior is disadvantageous to them individually but beneficial to the group as a whole and was thus seen by some to support the group selection theory.

And you're aware of Systematics, the branch of biology that attempts to establish genealogical relationships among organisms. Also, it is concerned with their classification. The three primary camps in systematics are cladists, pheneticists, and evolutionary taxonomists. Remember we constructed phylogenetic trees based on the method of Maximum Parsimony which states that - the tree with the minimum number of trees should always be chosen (Felsenstein 1988).

Now you know Francis Crick, of course.. He has commented on potential limitations of Occam's razor in biology. He advances the argument that because biological systems are the products of (an on-going) natural selection, the mechanisms are not necessarily optimal in an obvious sense. He cautions that 'While Ockham's razor is a useful tool in the physical sciences, it can be a very dangerous implement in biology. It is thus very rash to use simplicity and elegance as a guide in biological research.'


Mind you, this does not hold true for Dr. Gregory House M.D.

When discussing Occam's razor in contemporary medicine, doctors and philosophers of medicine speak of diagnostic parsimony. Diagnostic parsimony advocates that when diagnosing a given injury, ailment, illness, or disease a doctor should strive to look for the fewest possible causes that will account for all the symptoms. This philosophy is one of several demonstrated in the popular medical proverb 'when you are in Texas and you hear hoofbeats, think horses, not zebras.' While diagnostic parsimony might often be beneficial, credence should also be given to the counter-argument modernly known as Hickam's dictum, which succinctly states that 'patients can have as many diseases as they damn well please.'


Guess, where does it apply when put to use in establishing the existence of God?

In the philosophy of religion, Occam's razor is sometimes applied to the existence of God; if the concept of a God does not help to explain the universe better, then the idea is that atheism should be preferred. Some such arguments are based on the assertion that belief in God requires more complex assumptions to explain the universe than non-belief. On the other hand, there are various arguments in favor of a God which attempt to establish a God as a useful explanation.

These guys will do anything to get their things right! Damn you Occam's razor, you could've been maybe, a little more plausible at times..?

An important thing to note here, will be to know that William of Ockham, being a Friar, was himself a theist - he believed in the existance of God and thus, in the validity of scripturess..

At last, Controversies and Anti-razors

Galileo Galilei lampooned the misuse of Occam's razor in Dialogue. The principle is represented in the dialogue by Simplicio. The telling point that Galileo presented ironically was that if you really wanted to start from a small number of entities, you could always consider the letters of the alphabet as the fundamental entities, since you could certainly construct the whole of human knowledge out of them.

Anti-razors have also been created by Gottfried Wilhelm Leibniz (Divya, rings a bell..? Something about the internship/training we did?). Leibniz's version took the form of a principle of plenitude, the idea being that God created the most varied and populous of possible worlds.

'The variety of beings should not rashly be diminished.'


  1. As a science researcher, I find people tend to forget that when an experiment doesn't work, it could just be due to the simplest thing! As a blog writer on science communication, I try to write the simplest way ;)
    Feel free to hop over to and follow me back ;)
    Keep up the good work!

    1. Well, I'm a budding researcher, so as to put that out subtly.. (absolutely got my tongue-in-cheek!) yeah true, happens to us each time in lab! haha.. followed your blog, will surely keep up! and thank you.. =)