Authenticity sells. The search for authenticity is the theme of many successful films, books, and plays (from About a Boy to Dead Poets Society and Peer Gynt), countless self-help books advise us how to become more authentic, authentic food and travel has never been so popular, and politicians try to garner votes by branding themselves as authentic. Marketing and politics have long discovered authenticity as a useful label to sell goods and candidates.

Boris Johnson and Donald Trump are recent examples of politicians who presented themselves and were perceived by many as particularly authentic. At the same time, both are widely believed not to take the truth too seriously, and even to be habitual liars. This seems like a contradiction. Can you be an authentic liar? Is calling a liar authentic just misleading marketing? Figures like Johnson and Trump can prompt us to reconsider and clarify what we mean by a concept like authenticity as well as how we should relate to ourselves and express ourselves to others.

We all lie, of course. If any small lie leads to a verdict of inauthenticity, we all fail at being authentic. Authenticity is an ideal concerned with who you truly are. By far not every lie you tell seems to be defining or expressive of who you truly are. The lies that most powerfully threaten authenticity are lies about central aspects of who you are as a person – lies about personally significant beliefs, values, goals, wishes, character traits, emotions, or abilities and aptitudes. Politicians who lie about their beliefs and values to convince voters are an all-too-common example of this. Keeping this focus on personally significant lies in mind, let's take a look at the concept of authenticity.

Authenticity is a complex concept that combines multiple traditions, some of which are diametrically opposed. Rousseau, Herder, and the romantics, as well as Nietzsche, Kierkegaard, Sartre, and the existentialists have shaped this ideal. To do justice to the complexity of the concept of authenticity and human nature, authenticity is best understood as a multidimensional concept. The ideal of authenticity can provide guidance on how we should relate to, know, define, and express ourselves.

What many people think of first when they hear ‘authenticity’ is being in touch with their true self, a type of knowledge. Authenticity as self-knowledge means understanding and knowing who you truly are. You may achieve self-knowledge, for instance, through introspection and reflection or conversations with friends and family. As long as your self-conception coincides with your true self, you are authentic. Thus, if you know that you are a liar and you understand why you lie, you are authentic.

But arguably, an important part of being authentic is how you express yourself to others. For example, a person who is free of all delusions about who they are, but is forced to hide their identity from others, is unable to live an authentic life. According to authenticity as truthfulness, to be authentic means to express truthfully and openly what you think or feel. This seems to imply that a liar would be inauthentic.

However, we can distinguish two different kinds of truthfulness. One is a careful attempt at being as honest and transparent as possible. It requires self-knowledge and is concerned with getting to the heart of the individual. According to this view, you achieve authenticity in a two-step process. First, you have to know yourself. Second, you have to live and present yourself to others according to who you truly are. We can call this authenticity as self-knowledge and self-expression.

Now, what if, after careful introspection and reflection, you find out that you truly are a notorious liar? In this case, another dimension of authenticity provides further guidance. Authenticity also demands defining, being, and expressing yourself largely free of the restrictions of social norms and conventions. This authenticity as independence entails not taking the easy route and misrepresenting who you are or what you think and feel to achieve your goals, such as to impress others or get a job. Thus, the reasons for lying matter. A person who is lying because she is ashamed of what she did or someone who lies because he wants to sway potential voters would be inauthentic. A person who lies just for the sake of it, for instance, because she just likes to confabulate and trick others, could do so authentically. She does not lie to appear to follow others' norms and expectations.

The second notion of truthfulness is truthfulness as an unfiltered expression of thoughts and emotions. You do not have to truly know yourself to be truthful in this sense, you should just not be a phoney. Your self-expression should coincide with your experiences and self-conception, no matter whether you are self-deluded. This is authenticity as self-expression. According to this dimension of authenticity, a person who is telling falsehoods without being aware of it would be authentic, but he would not qualify as a liar. A true liar would always be inauthentic.

Another, closely related, dimension of authenticity requires that your self-expression coincides with your true self. If you lie you are inauthentic, unless you are self-deluded and just happen to tell the truth about yourself even though you think you are lying.

Lastly, I want to mention authenticity as coherence. According to this account, your true self consists of your mutually cohering personal characteristics – the ones that fit together, make sense in light of each other and support each other. To be authentic, you should live according to your cohering values, goals, traits, beliefs, and other personally significant characteristics. Thus, as long as lying is consistent with who you are, with your overall values, goals, and other characteristics, you are an authentic liar.

So where does all of this leave us with the question of the authentic liar? First of all, it shows that authenticity is a complex concept that comes with a broad range of considerations about the authenticity of lying. The reasons for lying, insight into those reasons, and overall personal characteristics play important roles for understanding whether a liar is authentic. It also means that we need to do some work to find out which dimensions of authenticity provide us with an ideal that is worth pursuing. Why should we value authenticity as self-expression or authenticity as independence? We might also be inclined to say that all dimensions of authenticity are worth pursuing. In this case, authenticity would demand congruence between the true self, one's self-conception, and one's self-expression, as well as coherence. Most liars fail to be authentic across many of those dimensions and all of them fail regarding authenticity as self-expression. Overall, if you care about authenticity, you should probably refrain from personally significant lies – being honest is definitely less threatening to authenticity than lying.

The reason why many have considered figures like Boris Johnson and Donald Trump as authentic probably has to do with the image they cultivate as not restricting themselves by social norms and expectations (authenticity as independence). For a long time, their lies did not seem to hurt their image as authentic, or at least not enough to overshadow their authenticity as independence. However, an opinion article suggests that at least at the end of his position as prime minister, Boris Johnson has stretched it too far and is now more likely to be perceived as devious and corrupt than warmly authentic.Footnote ¹ The image of the authentic liar seems to have its limits.