One-sided coin looks like the opposite of diversity. Diversity requires multiple varying possibilities. The opposite of diversity is a single possibility, and this is called a one-sided coin.
For example, someone deemed “monotonous and boring” may be derogatorily called a “one-sided coin”. Another example: A proponent of diversity may label someone committed to a single cause as a “one-sided coin” and even call him/her “too ideological”. In fact, ideology at its purest is to deem oneself above ideologies (post-ideological) and “diversity” is a notion that functions quite ideologically in this sense.
Badiou’s (and Žižek’s) “fidelity to a Truth-Event” is exemplary of the one-sided coin that I would like to redeem in face of the contemporary panegyrics to the diverse. This is why I put “fidelity to the Žižek-Event in philosophy” as a requirement in the Žižekian Analysis Call for Blog Posts.
On the other hand, it’s somewhat incorrect to oppose the one-sided coin to the diverse. The one-sided coin should be grasped as the disavowed heart of the diverse. Diversity presently functions in an ideological way only because its true origin is systematically disavowed. Instead of opposing these two notions, we should ask: What inaugurates diversification in the first place? In other words, what is at the heart of the combinatorial? 
If we accept the symbolic nature of diversification through identifying with signifiers, we can easily find the answer: The unary trait is at the heart of the diverse. Unary trait is the primitive form of the signifier as a mark, it’s the elementary point of identification with the ego ideal.
The one-sided coin is essentially the unary trait. To return to our example above: For a Marxist one-sided coin, the Marx-Event in history is the unary trait that forms his/her point of identification with the ego ideal. For a Žižekian one-sided coin, the Žižek-Event in philosophy is the unary trait that does the same. So what is so special about a one-sided coin?
In an ordinary two-sided coin, “Heads” and “Tails” are presupposed to be the opposed particular alternatives that are pitted against one another in a zero-sum game of competition. This is the heart of the concept of probability. According to the famous axioms of probability, all probabilities must exclude one another and sum up to 1. Since the ideology of diversity is based on this exclusivity of probabilities, “intersectionality” is presented as the remedy that is supposed to improve this only game in town.
The one-sided coin breaks entirely with the zero-sum game of multiple exclusive probabilities. But it’s not opposed to diversity. The one-sided coin is at the heart of diversity in at least two senses:
1) Every diversification takes place through the unary trait as the one-sided coin at its concealed and disavowed true origin.
2) “Diversity” is the specific one-sided coin that colors the entire contemporary “post-ideological” ideology.
In other words, the one-sided coin as the unary trait is the drive of repetition that is revealed to be at the heart of the apparent diversity of contemporary desires.
Işık Barış Fidaner is a computer scientist with a PhD. Admin of Yersiz Şeyler (Placeless Things) blog, Admin/Editor/Curator of Žižekian Analysis, and one of the admins of “Žižek and the Slovenian School” group on Facebook. Twitter: @BarisFidaner
 See “Spatial and Combinatorial”