The proprietary effect of the fulfilment of the suspensive condition in a conditional transfer is traditionally explained by the retroactive effect of the fulfilment of the condition. In the nineteenth century, various writers wondered whether this explanation was satisfactory. Jhering proposes a different theory for the explanation of the proprietary effect of the fulfilment of the condition. In his article ‘Passive Wirkungen der Rechte’, he creates a theory based on Roman law in which the proprietary effect is explained by the passive Wirkungen of the ‘legal bond’ of the asset. In his theory, the fulfilment of the suspensive condition has a proprietary effect without using retroactive effect of the fulfilment of the condition. Despite the fact that the transfer of rights is postponed until the condition is realised, the asset is already ‘legally bound’ because of the conditional transfer. This ensures that the ownership is transferred if the suspensive condition is fulfilled. Jhering’s theory is insightful for Dutch law because the Dutch Civil Code excludes retroactive effect of the fulfilment of the condition. The doctrine of the ‘legal bond’ of the asset also corresponds with the intention of the transfer in the case of a suspensive condition. It fits within the Dutch system of property law and explains in a simple manner the proprietary effect of the fulfilment of the condition.