In this work we intend to highlight some questionings regarding the application of the theory of the equivalence of the conditions as well as the theory of adequate causation in the resolution of complex causal issues. Said complex issues involve factual characteristics that do not allow determining harmful effects for later qualifying them as damages (at least from a sensible sense of justice). Regarding the first theory, it is stated that since there are damages whose origin can only be attributed to omissions, the causal approach of mental suppression loses relevance; The same thing happens in contexts of alternative or hypothetical causation, in which it is essential to resort to statutory criteria to respond to these complex issues. Regarding the latter theory, it is argued that it reveals complexities, mainly its connection with foreseeability, which can be seen both in the context of the an debeatur and of quantum respondentur, which are part of the stages of any liability judgment. This occurs when determining the scope of those who are deemed liable. In this latter case the distinction between adequate causation and negligence is not really appreciated; the same occurs in the determination of damages; if this latter theory were followed, the principle of comprehensive damage provided for by our legal system would be violated, at least for non-contractual liability, in accordance with the provisions of article 2329 of the Civil Code (CC).