This is a book about truth, so let us start with a definition of truth.
Truth is an observable phenomenon that can be independently verified, not more, not less. Truth and fact are synonyms. The opposite of truth is a falsehood. And if a falsehood is spread with the knowledge that it is a falsehood, it becomes a lie.
Why does truth matter?
In your life, you must make decisions all the time, decisions big and small. You must decide which profession to pursue, which university to attend, which job to take. You must decide to marry or not to marry, to have children or not to have children, to buy a home or to rent. You must decide where to live, which ideologies to support, how much money to save for retirement. You must decide if you can trust your doctor, your auto mechanic, you favoured politician. You must decide which book to read, which film to watch, what you will have for dinner. ...
Decision making is the process of arriving at your choice. It is not a trivial process. Here are the steps:
1: You find yourself in a situation where you must make a decision.
2: You identify your goals.
3: You identify alternative options.
4: For each option, you try to predict the consequences of pursuing it.
5: You assess the consequences of each option in relationship to your goals.
6: You choose the option that comes closest to your goals.
Understanding your situation, identifying your goals, identifying your alternative options, and trying to predict the consequences of an option all require information. This information may be true, incomplete, inconsistent, or false. The best decisions will be based on true and complete information. And the decisions you make, the options you choose to pursue, will determine your well-being. Consequently, truth matters.
We humans are not the only species that faces decisions. All organisms have been selected for survival and reproduction. From the unicellular paramecium, to the shy octopus, to the industrious honeybee, to the mountain gorilla. Both survival and reproduction require decisions.
Options may present themselves on evolutionary timescales (physiological options, morphological options) or on an ecological timescale (behavioural options). Physiological options and morphological options are possible solutions to big and slow problems: Aerobic or anaerobic respiration? Tracheae, gills, or lungs? Behavioural options are possible solutions to small and fast problems: Where and when to look for food? Which competitors to fight? Where and when to hide and sleep? Where and when to mate, and with whom?
Life depends on knowing the truth. Literally.