Explaining the Criteria for Recognizing the Multiplicity or Unity of Personality in Conjoined Twins Based on Imamiyyah Fiqh and its Effect on Criminal Law

In conjoined twins, the connection of two bodies to each other leads to the suspicion of multiplicity or unity of personality. In other words, in relation to this type of person, it is doubtful whether these two bodies belong to two independent personalities or whether they belong to a single personality in which part of the extra limbs is seen. Taking advantage of descriptive-analytical method of research, the present study seeks to examine the various criteria in determining the unity or multiplicity of conjoined twins. The most important findings show that the fiqhi rule in this issue is the :::::union::::: of sleep and wakefulness or separation of the two, which itself is rooted in more important evidence such as the multiplicity or unity of the brain or soul, and this reveals the issue of multiplicity or unity of personality in the conjoined twins. Conversely, this rule and criterion is in accordance with the medical rules of the issue, that is, the unity or multiplicity of vital organs of the body, since according to the foqaha (Islamic jurists), the sign mentioned in fiqh is only one of the criteria for this matter, and anything that can help in recognizing this matter is sufficient. Indubitably, one of the most important pieces of evidence in recognizing the mentioned issue is the multiplicity or unity of vital organs in the individual, as the vital powers and the leading organs of the body exist in each person as a unit, and thus, their multiplicity indicates the multiplicity of personalities.