In his Philosophical Investigations, Wittgenstein wrote that, “The aspects of things that are most important for us are hidden because of their simplicity and familiarity.”
The curiosity that is trust is no exception to this rule, and, it’s safe to say, there is no universally accepted definition of trust.
The Trust Conundrum
On that, Jeffrey M. Courtright, in ‘Thinking Through the Phenomenon of Trust: A Philosophical Investigation’, well explains the problem of defining trust:
“Despite its pervasive presence and the vital role that it plays in human relationships of all sorts, we seem not to notice or to pay much attention to trust until it is betrayed or called into question. As a consequence of such invisible familiarity, trust is very difficult to define or explain. We all seem to know what trust is, but when asked to define or explain it, we are often at a loss for words.”
Available definitions of trust are complex, and vary over time by discipline, context, circumstance, and culture. For example, the Trust Over IP Foundation echoes Courtright in their definition of trust: “Trust is defined by the context, outcome, and significance of our experiences. Thus, trust is dynamic.
The conundrum of ‘to trust’ or ‘not to trust’ is never binary; it is fluid, changing over time and circumstance. Trust is an integral neurological component, a survival instinct that allows us to work together for common goals, build healthy relationships, establish a healthy society, and be innovative in our approach to everyday challenges.”
The Definition Of “Trust” Changes Over Time
As the definition of the word “Trust” is “fluid, changing over time and circumstance”, according to the Trust Over IP Foundation, let’s consider how others have defined this ambiguous word throughout history:
550 BCE: “Abandon weapons first, then food. But never abandon trust. People cannot get on without trust. Trust is more important than life.” – Confucius
500 BCE: What does the bible say on trust? As presented in the ESV version of the Bible, the word “Trust” is found primarily in the Psalms portion of the Old Testament. For example, in Psalms 20:7 it is written: “Some trust in chariots and some in horses, but we trust in the name of the Lord our God; They collapse and fall, but we rise and stand upright.”
400 BCE: What did Socrates say about trust? “Trust, in its relation to the relative truth and clarity of objects of knowledge, is situated above imagination (εἰκασία). According to Socrates, trust, as a kind of power and affection of the soul, is related to ‘the animals around us, and everything that grows, and the whole class of artifacts (σκευαστὸν),’ [by which he means] the everyday sorts of things which human beings encounter as they navigate their daily lives, [but] generally take for granted.” – Stephen Harris Mendelsohn
How was “Trust” defined during the Medieval Ages? According to etymonline.com, the definition of the “Trust” changed in important ways from the 13th through 16th centuries:
c.1200: Trust was defined as “reliance on the veracity, integrity, or other virtues of someone or something; religious faith.”
c.1300: Trust was defined as “reliability, trustworthiness; trustiness, fidelity, faithfulness.”
c.1400: Trust was defined as “confident expectation” and “that on which one relies.”
c.1500: The word “Trust” became a legal word – “confidence placed in one who holds or enjoys the use of property entrusted to him by its legal owner.” By mid-15c, the legal basis of the word “Trust” continued to expand, shifting to the definition “condition of being legally entrusted.”
1828: The 1828 version of Webster’s Dictionary defines “Trust” as, “Confidence; a reliance or resting of the mind on the integrity, veracity, justice, friendship or other sound principle of another person.”
1950: Knud Ejler Løgstrup makes the claim that “trust is basic”.
1978: In her book ‘Lying’, the moral philosopher Sissela Bok writes, “Whatever matters to human beings, trust is the atmosphere in which it thrives.”
1995: In ‘Trust’, Francis Fukuyama stated that, “Trust is the expectation that arises within a community of regular, honest, and cooperative behavior, based on commonly shared norms, on the part of other members of that community.”
1997: “The morality of the Information Age [is] a morality of trust”, according to Davidson & Rees-Mogg in ‘Sovereign Individual’.
1998: In his article ‘Not So Different After All: A Cross-Discipline View Of Trust’, D.M. Rousseau defined “Trust” as “a psychological state comprising the intention to accept vulnerability based upon positive expectations of the intentions or behavior of another.”
2008: In his book ‘The Little Teal Book Of Trust’, Jeffrey Gitomer wrote: “Trust is a form of faith.”
2010: In the paper, ‘The Dynamics Of Trust’, Bart Nooteboom stated: “A first definition of trust might be: ‘I trust when I am vulnerable to [the] actions of another, but I believe that no significant harm will be done’… Trust is based on some combination of feeling and reflection.” He continues with, “In trust there is a paradox of information”, and “The causal ambiguity of trust yields a plea for openness in communication.”
2015: Economist Andy Haldane wrote: “Trust is an altogether different animal. It is based on beliefs, not observable proofs. It is grounded in perceptions rather than evidence. It is as much a psychological state as a financial one. A clean balance sheet might instill confidence, but it need not repair trust. Because it is a moral judgment, repairing trust can be a slow and painstaking business.”
2020: In his article ‘Trust Models’, Vitalik Buterin defined “Trust” as: “The use of any assumptions about the behavior of other people.” Also in 2020, Edelman wrote: “Trust is the tie that binds us in our shared quest for a better future.”
2021: In “The Anatomy of Trust” Brené Brown said: “Trust is defined as: choosing to make what’s important to you, vulnerable to the actions of someone else. Distrust is defined as: what I shared with you, is not safe with you.”
A Comprehensive Definition Of “Trust”
Bringing together the above, the word “Trust” can be comprehensively defined as: a fundamental psychological and moral state of confident reliance on others’ integrity and intentions, characterized by the voluntary acceptance of vulnerability based on beliefs rather than proof, which serves as both a survival instinct enabling human cooperation and the essential atmosphere in which all meaningful relationships, communities, and societal progress thrive.
Final Thoughts
The journey through these definitions reveals something profound: while trust remains stubbornly difficult to pin down, certain threads weave consistently through millennia of human thought. From Confucius declaring trust more important than life itself, to Brené Brown defining it through vulnerability, we see trust persistently emerging as the invisible foundation of human connection.
What strikes me most is how trust definitions have evolved from the spiritual and communal (biblical faith, Confucian social bonds) through the legal and institutional (medieval property law, Fukuyama’s communities), to the deeply personal and psychological (Rousseau’s vulnerability, Brown’s emotional safety). This progression mirrors humanity’s own journey from collective to individual consciousness, yet paradoxically demonstrates that trust remains fundamentally about relationships—whether with divinity, community, institutions, or individuals.
Wittgenstein’s observation that opened this exploration holds the key: trust’s very familiarity makes it invisible to us. Like air, we only notice trust when it’s polluted or absent. The multiplicity of definitions doesn’t reveal confusion, but rather richness—trust operates simultaneously as survival instinct, social lubricant, economic enabler, and spiritual practice.
Maybe the real insight isn’t finding the perfect definition of trust, but recognizing that its indefinability is precisely what makes it so essential—fluid enough to adapt to any human context, yet solid enough to build civilizations upon.
Thanks for reading!