The principal type of academic writing in the humanities is critical writing. The term ‘critical’ can be misleading, as it might appear to suggest that it expresses a negative view of its subject, that is, that it criticizes things. This is not exactly the case, but it does highlight an important aspect of critical writing, which is that it closely analyses its topic in order to understand it more fully. So, although the term does not imply taking a negative view of things, we can say that it involves close and careful examination.

In academic writing in the humanities (as in all academic writing, of course), you need a topic and an opinion on that topic. For example, you might believe that Protestantism contributed to the growth of capitalism. But it is not enough to simply have this opinion; you need to develop it through argument that takes into account other recognized ideas or sources on this topic, and to use these ideas, with which you will show your agreement or disagreement, as a way of building up your own point of view. By doing so, you will be reviewing the evidence on this subject in order to reach a reasoned conclusion. This is critical writing.

There are many different approaches that can be taken in writing critically, but essentially it has two important aspects:

• Critical writing takes into account not just one but a range of sources.
  
  
• Critical writing examines and assesses its sources.

To return to your theory on Protestantism, to write critically on this subject you would need to research work (‘critical sources’) that discusses this idea. You would find that some authors (also known, particularly in literary studies, as ‘critics’) claim that the highly individualistic nature of Protestantism contributed to capitalism because it emphasizes the consequences of individual responsibility. Let us say that this opinion is close to your own, so you want to use it in your text. But you need more than just one source, otherwise your argument will be too limited and one-sided. Then you discover that other critics point out that capitalism also developed in regions where Catholicism has never been displaced (such as Bavaria, for instance, or parts of Scandinavia), which tends to complicate your own view. You could ignore this opinion, as it does not support your own idea; but this would be academically dishonest and would result in an argument that did not take into account a broad range of views. That is, you need to examine and assess the sources that support and that undermine your own idea.  

Notice that your main tasks in writing critically, apart from eventually describing your reasoned conclusions, are to evaluate and analyse your sources. You do this by looking at how relevant they are to your topic; how strong or weak their arguments are; and how balanced and reasonable they are (a source that does not take other views into account or that makes too many unsubstantiated claims is not likely to be a positive contribution to your text). But you also need to make sure that your sources are reliable, that they come from recognized specialists or at least from people whose work is accepted by your own academic area. And you need to make sure that you are using sources that are acceptably recent: a rule of thumb in the humanities is that most of your sources should have been published within the last 20 years; anything earlier than that is unlikely to reflect most recent debate (although there are always important exceptions to this, and your supervisor will guide you on this matter).  

The kinds of questions you need to ask yourself when writing critically are the following:

• Is my argument sufficiently supported by other sources? Have I (or have any of my sources) made claims that have no evidence?
  
  
• Am I limiting my sources and my own analysis to only one point of view? Am I taking distinct and maybe contradictory opinions into account?
  
  
• Am I adequately examining my own opinion and those of my sources? Do I clearly indicate the strengths and weaknesses of these views?
  
  
• Are these sources reliable? Are they recognized within my own academic area?
  
  
• Are these sources and their opinions relevant to my topic?
  
  
• Are these ideas sufficiently recent?
  
  
• Am I presenting all sides of the argument in a balanced way? Do I give too much emphasis to one point of view?
  
  
• Am I being honest about the limitations of my own opinion? (It is valid and responsible to accept that a view, however compelling, might need more evidence or discussion?)

In your own project, you might eventually find that, although certain studies point to ideas that are contrary to your own opinion, on balance your view is supported and justified by the sources you have assessed. Although it is also worth remarking that academic enquiry means accepting that your arguments have been disproved, or at least that your own findings have limitations. Whatever your final opinion, however, it will have been shaped by a consideration of the sources, and this is basic to critical writing.