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Tutorial: Improve Your Critical Reasoning Skills

One simple way to improve your critical reasoning abilities is to practice. Practice deconstructing arguments, questions, statements – everything. You do this by spotting the assumptions on which the statement is founded.

An assumption is something that is assumed to be true, but which is not always explicitly stated. Assumptions are like the foundations on which arguments are built. If you start mucking about with them, questioning them, then pretty soon things start to fall apart.

Spot The Potentially Fallacious Assumptions Underlying These Questions And Arguments:

[Highlight the text between the square brackets to reveal the answers]


Hitler was responsible for the deaths of millions. He was clearly an evil person.

[The assumption here is that killing is bad. This is a very popular assumption, though it is regularly challenged by laws referring to self defense and, in some places, capital punishment.]


The Irish health service is a disaster and it is only getting worse. This is apparent from the fact that, over the past few years, the number of patients waiting for hospital beds has increased dramatically.

[Assumption 1: ‘the fact that’ the waiting list for beds has increased. This is effectively an assumption because it cannot be verified within the confines of this essay and must therefore be assumed true.

Assumption 2: Patients waiting for beds is indicitive of a poor health service. Rather than, for example, an infectious epidemic or a ‘greying’ population]


If the economy continues to decline, how will working-class families feed their children?

[This question opens with the proposition that the economy is in decline. The question becomes invalid once we challenge this initial assumption. Which economy? In what way is it in decline? And how does that relate to starving children?]


Fruits and vegetables are helpful to eat. They lower cholesterol and reduce the risk of getting cancer. You should eat them every day if you want to succeed in life!

[Assumption: Helpfulness assumes the existence a goal. Are fruits and vegetables unequivocally helpful? No. It depends on what you’re trying to achieve. What if someone was intentionally trying to elevate their cholesterol levels – or just starve themselves – as part of an experiment? It’s hard to understand why someone would do this, but thinking in this way allows us to see the loose logic for what it is.]


If a tree falls in the forest, and nobody is there to hear it, will it make a sound?

[This question assumes the tree in the forest exists independently of its observer – that it is there when nobody is looking. This might seem like a reasonable assumption for most people to make, but it is an assumption nonetheless. This question is not actually a question, but a veiled statement about the existence of an objective reality. Deep huh?

Also, if you wanna really get into it: you might also question the definition of ‘sound’.]


Newspapers provide an endless supply of arguments to practice deconstruction. If you had difficulty with these start with the tabloids and work your way up. Look out for lies of omission, cliches, and popular, rarely-challenged beliefs which form the basis for the stories.

Final Point: Assumptions are not bad. They are an inevitable aspect of argument construction, and communication in general. The important thing is to cultivate an awareness of the assumptions being made – especially when it is you who is writing them on an exam.