Let us think in terms of mathematical formulas once again (for the previous references to mathematical formulas, see Part 8). Under the Rawlsian philosophy, only Formula (1) is valid, which means that the time factor is not reflected in the value of the system of justice. The system of justice is valuable in that it provides an optimal means to pursue individual goods (within the same generation). From the position of our moderate comprehensive doctrine, which maintains that individuals’ actions are valuable because they contribute to the renewal of the system of justice through innovations, Formula (2) is valid. In this case, Formula (3) is arrived at through Formulas (1) and (2).
(however, \(0<α<1, \:0<β<1, \:γ=α×β)\)
The present moral value of the system of justice (\(q_{t}\)) is determined by its future value (\(q_{t+1}\)). Given the chain of value that extends across time, the present moral value of the system of justice (\(q_{t}\)) is determined by its moral value in the infinite future (\(q_{∞}\)). In other words, the present moral value of the system of justice (\(q_{t}\)) may be understood to be a kind of “asset price (Note 1).”
The system of justice (\(k_{t}\)) itself may be understood to be an intergenerational, ultra-long-term asset that is assumed to be passed on indefinitely across generations. If the present generation is to undertake acts of self-sacrifice in order to resolve intergenerational problems, preserving intergenerational assets may be the motivation for doing that. For example, let us assume that if nothing is done to deal with global environmental problems at present (\(year\:t\)), human society will collapse \(N\) years later. In this case, the value of the system of justice \(N+1\) years later (\(q_{\{t+N+1\}}\)) becomes nil. As a result of the chain of value under Formula (4), the following equation is arrived at: \(q_{t}= q_{\{t+1\}} = 0\) (the present value of the system of justice also becomes nil). This means that the value of life (moral value) for the individuals of the present generation (\(p_{t}\)) is also reduced to nil as follows: \(p_{t} = β q_{\{t+1\}} = 0\). To avoid this situation, the people may reach an agreement on undertaking the acts of self-sacrifice that are essential in order to resolve the global environmental problems.
Let us consider a case in which the collapse of human society \(N\) years later can be prevented if the present generation pays the cost of environmental protection measures (\(X\)). The value of the present generation’s actions is expressed as \(p_{t} c_{t}\) if the cost \(X\) is not paid, whereas the value is expressed as \(p_{t} (c_{t}–X)\) —i.e., the value declines—if the cost is paid. In a world where the Rawlsian theory of justice prevails, although Formula (1) is valid, Formula (2) is not, because the value of individual virtue (\(p_{t}\)) is a given. In that world, the present generation chooses not to pay the cost \(X\) because paying the cost means a smaller benefit (\(p_{t} (c_{t}– X)\)) compared with the benefit to be gained if the cost is not paid (\(p_{t} c_{t}\)). Therefore, in the world that works under the Rawlsian theory of justice, the people cannot reach an agreement on paying the cost of environmental protection measures, with the result that the environment will continue to deteriorate.
On the other hand, under the theory of innovation-driven justice that we have been discussing in this paper, we arrive at a different conclusion. In a world where the theory of innovation-driven justice prevails as the people’s worldview, both Formulas (1) and (2) are valid. As a result, although the benefit for the present generation is higher than zero (\(p_{t}> 0\)) if the present generation pays the cost of environmental protection measures \(X\) just as in the previous case, the benefit is nil (\(p_{t}=0\)) if the cost is not paid.
In this case, the benefit is expressed as \(p_{t} (c_{t}– X)\) if the cost \(X\) is paid, whereas it is expressed by \(p_{t} c_{t} = 0 ×c_{t}\), if the cost \(X\) is not paid, which means the benefit is nil. If it is assumed that the net consumption is higher than zero (\(c_{t}–X > 0\)), the benefit for the present generation to be gained if the cost \(X\) is paid is greater than the benefit to be gained if the cost is not paid. As a result, the people of the present generation agree on implementing environmental protection measures.
As illustrated by this case, if we accept the moderate comprehensive doctrine’s proposition that the value of individual goods depends on the value of the system of justice, undertaking acts of self-sacrifice in the fight against global warming would be considered to be a rational decision on the part of the people of the current generation from the viewpoint of preserving the present value of life (\(p_{t}\)) for themselves. What is necessary is to conceive a new vision of intergenerational ethics that reflects this.
