Knowledge can be actual or constructive and exists on a graded scale.
The courts recognise five categories of knowledge:
- Actual knowledge
- Wilfully shutting one’s eyes to the obvious
- Wilfully and recklessly failing to make such enquiries as an honest and reasonable person would make
- Knowledge of circumstances that would indicate facts to an honest and reasonable person
- Knowledge of circumstances that would put an honest and reasonable person on enquiry
The second and third bullet points are often referred to as species of actual knowledge. The fourth and fifth bullet points are forms of constructive knowledge.
The Macquarie Dictionary (4th ed, 2005) defines the verb ‘know’ as: ‘to perceive or understand as fact or truth, or apprehend with clearness and certainty … to be cognisant or aware of, as of some fact, circumstance or occurrence; have information, as about something’. And the noun ‘knowledge’ has a concomitant meaning: ‘the fact or state of knowing; perception of fact or truth; clear and certain mental apprehension … the state of being cognisant or aware, as of a fact or circumstance’.
For legal purposes a person’s knowledge of a fact or circumstance does not mean that that fact or circumstance is immutably so.
In contrast if someone has a belief about a state of affairs the High Court in George v Rockett (1990) tells us (at least for the purposes of the criminal law) that:
“Belief is an inclination of the mind towards assenting to, rather than rejecting, a proposition and the grounds which can reasonably induce that inclination of the mind may, depending on the circumstances, leave something to surmise or conjecture.”
This is to say that belief may be something less than knowledge.