本书基于自由之可能这一哲学根本问题，对费希特知识学理论的建构进行了深度阐释，并在此基础上对比了费希特的自由理论与马克思以“对象性活动”概念为核心的自由理论，表明了两种理论之间具有的相关性。本书以自由的构建为逻辑脉络分析了费希特前后两个版本的知识学：《全部知识学的基础》和《知识学新方法》，梳理出两个版本中自由体系的基本要素、推演逻辑及其理论的最终结果，指出《知识学新方法》对《全部知识学的基础》这一版知识学中的基本构件，即自我、非我及二者之间的关系进行了修正。这种修正指向一个理论目的，即为一种自由理论之可能做辩护。本书认为，费希特以自我为基础的自由理论是一种从主体出发向感性世界进行跨越的尝试，它既试图克服因康德对“物自体”的承认导致的二元论，也试图弥补唯心主义一直以来无法走出意识内部的理论缺陷。在费希特联结理性世界与感性世界的尝试中，想象力凭借其“摆荡”的特性被认作是桥梁和关键，并且其重要性在《知识学新方法》中得到了极大的提升。想象力概念之所以在费希特的理论中具有如此重要的地位，是因为费希特认为想象力作为一种无定形的力量以自由为本质，这使得它能够在理智世界与感性世界之间穿梭，将二者统一起来。费希特的这个推理逻辑建立在他如下信念之上，即自由作为一种跨越性能力，能够使自我超出主体领域达至感性世界。

然而，费希特这一理论结构以及其中包含的实践要素被自我的绝对设定能力所掩盖，其后继者无论是谢林还是黑格尔，都只将注意力集中于费希特的绝对自我概念。经过青年黑格尔派的过渡，特别是在吸收费尔巴哈的感性理论之后，马克思在他的实践理论中发展出了类似的自由体系模型。在《1844年经济学哲学手稿》中，马克思以对象性活动为核心在感性的人与自然之间建立起的多重关系，在结构上与费希特在知识学中建立起来的自我与非我之间的关系相类似。借助这个结构，马克思建立起了以能动的感性主体为承担者的对自然界的改造模式，在其中，感性的人实现其本质和自由。这种由结构的类似生发出来的理论上的共性证明，费希特的理论影响了马克思，特别是青年马克思的实践哲学。

关键词：自由；想象力；对象性活动；实践

Abstract

Based on the fundamental philosophical question of the possibility of freedom,this book provides an in-depth explanation of the construction of J.G.Fichte's Wissenschaftslehre. Taking this as the basis, it compares J.G.Fichte's theory of freedom and Karl Marx's theory of freedom,the latter takes the concept of“Gegenstandliche Tätigkeit”as the core, and shows the correlation between the two theories.

This book takes the construction of freedom as the logical context to analyze Fichte's two versions of Wissenschaftslehre:Grundlage der gesammten Wissenschaftslehre（Foundations of the Entire Science of Knowledge） and Wissenschaftslehre nova methodo（Foundations of Transcendental Philosophy）,and sorts out the basic elements,the logic of deductions and the final result of the system freedom of in this two versions. It points out that Wissenschaftslehre nova methodohas revised the basic components in the Grundlage der gesammten Wissenschaftslehre,namely das Ich,das NichtIch and the relationship between them. This revision points to a theoretical purpose of defending the possibility of a theory of freedom. This book argues that Fichte's Ich-based theory of freedom is an attempt to leapfrog from the subject to the sensible world. It not only tries to overcome the dualism caused by Immanuel Kant's reservation of“thing-in-itself”, but also tries to make up for the theoretical defect that idealism has always been unable to go out of consciousness and reach the sensible world. In Fichte's attempt to connect the rational world and the sensible world,imagination is regarded as a bridge and a key by virtue of its“schwebend（hovering）”characteristic, and its importance has been greatly enhanced in Wissenschaftslehre nova methodo. The reason why the concept of imagination is of such importance in Fichte's theory is that Fichte believes that imagination,as an amorphous force,has freedom as its essence,which enables it to be able to interact between and shuttle between the intellectual world and the sensible world, unifying the two. The logic of Fichte's reasoning is based on his belief that freedom,as a transcendental ability,enables das Ich to transcend the realm of the subject and reach the sensible world.

However, the theoretical structure and the practical elements contained in Fichte's Wissenschaftslehre are overshadowed by the absolute“setzen”capacity of das Ich, and his successors, whether Schelling or Hegel,only focus on Fichte's concept of absolute Ich. After the period of the Young Hegelian, especially after absorbing Ludwig Andreas Feuerbach's theory of sensibility, Marx developed a similar model in his theory of practice. In the Economic and Philosophical Manuscripts of 1844, the multiple relations Marx established between sensible humans and nature centered on“Gegenständliche Tätigkeit”is structurally similar to the relationship between das Ich and das Nicht -Ich established in Fichte's Wissenschaftslehre. With the help of this structure, Marx established a model of the active subject as the implementer changing the natural world, in which the sensible human realizes his essence and freedom. This theoretical commonality arising from structural similarity proves that Fichte's theory of freedom has an influence on the practical philosophy of Marx.

Key Words:Freedom;Imagination;Gegenständliche Tätigkeit;Practice