The term is one of four such "idols" which represent "idols and false notions which are now in possession of the human understanding, and have taken deep root therein, not only so beset men's minds that truth can hardly find entrance, but even after entrance is obtained, they will again in the very instauration of the sciences meet and trouble us, unless men being forewarned of the danger fortify themselves as far as may be against their assaults. Besides idola tribus, there are also idola specus, idola fori and idola theatri. And so in this category are cases of people being misled by anthropomorphism. In more detail, Bacon enumerated several specific such barriers to science which are part of human nature, coming into this category:
"The human understanding is of its own nature prone to suppose the existence of more order and regularity in the world than it finds."
"The human understanding when it has once adopted an opinion draws all things else to support and agree with it."
"The human understanding is moved by those things most which strike and enter the mind simultaneously and suddenly, and so fill the imagination; and then it feigns and supposes all other things to be somehow, though it cannot see how, similar to those few things by which it is surrounded."
"The human understanding is unquiet; it cannot stop or rest, and still presses onward, but in vain. Therefore it is that we cannot conceive of any end or limit to the world, but always as of necessity it occurs to us that there is something beyond." Bacon gives as example the Aristotelian doctrine of final cause, which he says has "relation clearly to the nature of man rather than to the nature of the universe; and from this source have strangely defiled philosophy".
"The human understanding is no dry light, but receives an infusion from the will and affections; whence proceed sciences which may be called "sciences as one would." For what a man had rather were true he more readily believes."
"But by far the greatest hindrance and aberration of the human understanding proceeds from the dullness, incompetency, and deceptions of the senses; in that things which strike the sense outweigh things which do not immediately strike it, though they be more important."
"The human understanding is of its own nature prone to abstractions and gives a substance and reality to things which are fleeting."
Bacon said that the Idols of the Tribe "take their rise either from the homogeneity of the substance of the human spirit, or from its preoccupation, or from its narrowness, or from its restless motion, or from an infusion of the affections, or from the incompetency of the senses, or from the mode of impression".