Key Ideas in Summa I-II. Questions 1-5 (Happiness) and 6, 8-9, 13, 18-21 (WILLING THE GOOD)

painting of Thomas Aquinas kneeling in front of Jesus on the cross

Question 1--Humanity's Last End is Happiness

Human actions are reasoned, deliberate acts of the free will with an end in mind (1st). The rational nature knows the good in general and chooses among particular goods with an end in mind. The will functions as a kind of rational appetite (2nd). Human acts have a will toward a perceived good; in this sense, the end is present at every step of the journey (3rd). An end is needed for there to be intention on our parts, an indefinite search is finally incompatible with the good (4th). There is one last end, our happiness (our blessedness, the objective good), which orders everything; it orders our life's choices and meaning (5th). Humans choose things because they perceive in them their good, though often mistakenly. One need not always be thinking of the last end, such as with virtues like humor and speculative science (6th). All people desire the last end, that is "the fulfillment of their perfection," but not all agree on the manner or content of this perfection (7th). 


  1. How would you define "happiness," "joy," or "blessedness"? How would Aquinas' definitions differ?
  2. Do you think that all human actions are toward a perceived good?
  3. Must one always have the final end of blessedness in heaven in mind in life?

Question 2--What Happiness is Not

Human happiness cannot exist in wealth. Natural wealth (such as food, drink, clothing, housing, etc.) is to to support our human nature and is not an end in itself, while artificial wealth (currency) is sought to acquire natural wealth. We should take our estimation of wealth from the wise. The desire for natural wealth is finally finite, while artificial wealth can be desired in ad infinitum. Thus, it serves as "the servant of disordered concupiscence" (363). The more wealth we possess, the more we realize its insufficiency to bring happiness (1st). Human happiness cannot exist in honor for true honor is an account of some excellent quality in a person, so the happiness is a result of the quality. Honor does not make one excellent, rather it reflects what is already there (2nd). Happiness cannot exist in fame or glory because happiness exists in knowledge of another's happiness, and personal fame robs that. Human blessedness can only arise in praise from God who actually transforms us into the good in question (3rd). Happiness cannot exist in power since power can be used for evil, as well as for good. Happiness is not compatible with evil because it must satisfy of itself, lacking no good. Power without goodness will not satisfy (4th). Happiness cannot exist in bodily goods, such as health since they are ordained as means to a further end, and a human's end is in soul-body and not body alone (5th). Happiness does not consist in pleasure itself, rather delight accompanies various goods, so the best delight will result from the supreme good (6th). While happiness is a good of the soul, the soul exists in potentiality for something beyond itself and thus happiness constitutes something outside the soul (7th). Thus, no created good can constitute a person's perfect happiness. Perfect goodness, the universal good, is found in God alone, for God alone represents human happiness (8th).


  1. Do you agree with Aquinas' assessments of what doesn't bring happiness? Why or why not?
  2. Can there be intermediate forms of happiness along the way to the final form? Why or why not?

Question 3--The Definition of Happiness

Happiness is an operation since it is a person's last [teleological] act (2nd). A thing may belong to happiness in three ways: 1) essentially in being united to God; 2) as an antecedent to intellectual reasoning; and 3) as a consequence of happiness. The senses can function as an antecedent of happiness in this life, as an assistant to reasoning, and consequently in the blessed resurrection body (3rd). Happiness itself cannot exist in an act of the will since happiness is finally in the attainment of our last end; however, the will can be disposed toward this end. The will is subordinate to the actual intimate knowing of God, though it assists in the obtaining of this. Therefore, the delight that results from happiness does pertain to the will (4th). Happiness is an operation of the speculative intellect because it is contemplative in nature, which is for its own sake (5th). However, happiness is not speculative science because it is found in knowing God not in knowing about God (e.g theology) (6th). Happiness consists in the vision of the Divine Essence since humans are not happy as long as something higher remains to desire, and our intellect was designed for this perfection of perception and contemplation (8th).


  1. Why does Aquinas feel the will itself is not an act of the will?
  2. Do you agree with Aquinas' vision of the beatific vision as our final happiness and end? Why or why not?

Question 4--What is Required for Happiness?

Delight is necessary for happiness because it functions as instruction for it, is necessary for its life, helps us toward it, is attendant upon it, and is a key element in the Supreme Good (1st). This vision is the very cause of delight (2nd), and our volition will be completely subordinated to God's will (4th). The resurrected body is a necessity for the perfect happiness of the beatific vision because our enjoyment of God should overflow into our bodies which are a element of our perfection; however, incomplete happiness can be inexperienced without these bodies (5th). These bodies will be perfect, designed to see and enjoy God fully (6th). In this life, external goods are not necessary for happiness, but they often serve in an instrumental manner, signifying greater forms of happiness (7th). While friendship would not be absolutely necessary for happiness before the beatific vision, it can only add to and increase this perfect bliss (8th).


  1. Can anyone sin in heaven? Why or why not?
  2. Is bodily existence necessary for our final happiness? Why or why not?
  3. Is friendship necessary?

Question 5--The Attainment of Happiness

Humans can attain happiness provided their intellects can apprehend it and their wills desire it (1st). Humans in a blessed state can no longer desire anything since they have attained the greatest good, yet some can enjoy this more than others since they have a greater capacity than others (2nd). One can be happy in this life but not perfectly so (3rd), and in this life, imperfect happiness can be lost since we can lose contemplative happiness through forgetfulness or active happiness through vice. Perfect happiness in heaven cannot be lost since its perfect nature includes the assurance that it can never be lost and because the Divine Essence by its very nature excludes a desire not to behold it (4th). Imperfect happiness in this life can be obtained by human effort, but the perfect happiness is a gift of grace. Therefore, every person desires happiness since everyone desires to fulfill one's will, yet not everyone knows the true satisfaction of this desire and, thus, does not desire the true fulfillment of their desire (8th).


  1. Can one ever be truly happy in this life? Why or why not?
  2. Is it possible to be unhappy in heaven? How do you think Aquinas would explain the fall of Satan?

Questions 6, 8-9,13 [not in our assigned reading]

Human acts are voluntary since we act with a certain end in view (Q6.1st). Free will ceases to be free when it is compelled, though God has the right to compel us (4th). Violence, therefore, makes a compelled act involuntary (5th), while fear produces a more complex response, for actions done to avoid fear are still voluntary (6th). Concupiscence (unregulated, disordered passion) inclines the will in a certain direction, but it is still voluntary (7th). Ignorance can only be said to lead to an involuntary action when it denies the knowledge necessary to make a decision. Negligence, on the other hand, or intentional ignorance, should be discounted in these cases (8th).

We always will toward a good or an apparent good (Q8. 1st), so the will moves the intellect to actively act, while the intellect moves the will to determine whether to act, and sensation obeys reason (Q 9.1st-2nd). Astrological arguments, therefore, should be dismissed (5th).

Choice implies something belonging to the reason and to the will (Q13.1st), so irrational animals have sensation but not choice (2nd). One can finally only choose as to the means, not to the end itself; that is, every choice presupposes an end in question already before the choice is made (3rd). People choose freely, and not of necessity, since the final end of humans is happiness (6th).

Reflection Question: Why is free will necessary to our acts that lead to our final happiness?

Questions 18-21 [not in our assigned reading]

Ontological goodness resides in all actions, while human actions as intentional ethical choices can be evil in subtracting from the ontological goodness (Q18.1st). An act is good only when it is the right kind of act done with the right intention in the right circumstances (2nd). If a certain necessary circumstance is missing, an action otherwise right and well-intentioned is still evil (3rd). One, therefore, must consider the type of action, its particular expression, the surrounding circumstances, and the end in view (4th); one must consider both the quality of the action and the intention behind it (6th). It is possible that some kinds of actions by their nature are neither good nor evil (8th), and certainly some individual actions can be morally indifferent by virtue of not being done with any moral reasoning or intentions (9th). Sometimes an action's nature can be judged by its circumstances (10th) and at times by its degree (11th).

The goodness of the will is dependent upon the object presented to the reason (Q19.1st, 3rd), but finally its goodness is dependent upon eternal law (4th). The conscience can err, but one must obey what you believe to be right, even if this is finally wrong (5th). An erring conscience excuses an action (as sin) provided the ignorance is direct and not due to intentional negligence (6th). 

The intentional will is more important in judging an action bad than the type or action (Q20.1st); however, right will is not enough to make-up for the rest (2nd), so the exterior action and its interior choice are to be judged finally as one act (3rd) and it neither lessens punishment or increases reward if someone fails to do right (4th). Likewise, the unforeseen consequences of an action do not increase an action's goodness or malice (5th). Therefore, evil is a greater category than sin since an evil act done in good conscience is not sin though it remains an evil (Q 21.1st).

Reflection Questions:

  • How would you apply Aquinas' moral reasoning to a particular ethical dilemma, such as the person who kills someone with a gun by mistake?
  • What makes something a sin versus simply a tragedy?