为什么中世纪欧洲普遍采用封建制度，而不是由中央指派官员进行管理

Feudalism was a set of political and military customs in medieval Europe that flourished between the ninth and fifteenth centuries. Although derived from the Latin word feodum (fief),then in use, the term feudalism and the system it describes were not conceived of as a formal political system by the people living in the Medieval Period. In its classic definition, by François-Louis Ganshof (1944), feudalism describes a set of reciprocal legal and military obligations among the warrior nobility, revolving around the three key concepts of lords, vassals and fiefs. There is also a broader definition, as described by Marc Bloch (1939), that includes not only warrior nobility but the peasantry bonds of manorialism, sometimes referred to as a "feudal society". Because of multiple definitions and other issues, many now see the concept of feudalism as deprived of specific meaning, which has led in recent decades to many historians and political theorists rejecting feudalism as a useful way for understanding society.

Definition
There is no broadly accepted modern definition of feudalism. The terms feudalism or feudal system were coined in the early modern period (17th century), and were often used in a political and propaganda context.By the mid-20th century, François Louis Ganshof's Feudalism, 3rd ed. (1964; originally published in French, 1947), became a traditional definition of feudalism.Since at least the 1960s, concurrent with when Marc Bloch's Feudal Society (1939) was first translated into English in 1961, many medieval historians have included a broader social aspect, adding the peasantry bonds of manorialism, sometimes referred to as a "feudal society". Since the 1970s, when Elizabeth A. R. Brown published The Tyranny of a Construct (1974), many have re-examined the evidence and concluded that feudalism is an unworkable term and should be removed entirely from scholarly and educational discussion, or at least used only with severe qualification and warning.

Outside a European context, the concept of feudalism is normally used only by analogy (called semi-feudal), most often in discussions of Japan under the shoguns, and sometimes medieval and Gondarine Ethiopia.However, some have taken the feudalism analogy further, seeing it in places as diverse as ancient Egypt, the Parthian empire, the Indian subcontinent, and the antebellum American South.

The term feudalism has also been applied—often inappropriately or pejoratively—to non-Western societies where institutions and attitudes similar to those of medieval Europe are perceived to prevail.[8] Some historians and political theorists believe that the many ways the term feudalism has been used has deprived it of specific meaning, leading them to reject it as a useful concept for understanding society.

Classic feudalism
The classic François-Louis Ganshof version of feudalism describes a set of reciprocal legal and military obligations among the warrior nobility, revolving around the three key concepts of lords, vassals and fiefs. A lord was a noble who owned land, a vassal was a person who was granted possession of the land by the lord, and the land was known as a fief. In exchange for the fief, the vassal would provide military service to the lord. The obligations and relations between lord, vassal and fief form the basis of feudalism.

Before a lord could grant land (a fief) to someone, he had to make that person a vassal. This was done at a formal and symbolic ceremony called a commendation ceremony composed of the two-part act of homage and oath of fealty. During homage, the lord and vassal entered a contract in which the vassal promised to fight for the lord at his command. Fealty comes from the Latin fidelitas and denotes the fidelity owed by a vassal to his feudal lord. "Fealty" also refers to an oath that more explicitly reinforces the commitments of the vassal made during homage. Such an oath follows homage.

Once the commendation was complete, the lord and vassal were now in a feudal relationship with agreed-upon mutual obligations to one another. The vassal's principal obligation to the lord was to "aid", or military service. Using whatever equipment the vassal could obtain by virtue of the revenues from the fief, the vassal was responsible to answer to calls to military service on behalf of the lord. This security of military help was the primary reason the lord entered into the feudal relationship. In addition, the vassal sometimes had to fulfill other obligations to the lord. One of those obligations was to provide the lord with "counsel", so that if the lord faced a major decision, such as whether or not to go to war, he would summon all his vassals and hold a council. The vassal may have been required to yield a certain amount of his farm's output to his lord.

Depending on the period of time and location, feudal customs and practices varied, see examples of feudalism.

Feudal society
Main article: Feudal society
'Feudal society' expands on classic Ganshof. It includes in the feudal structure not only the warrior aristocracy, but the peasantry bonds of manorialism. This view was most famously put forth by Marc Bloch.

Emergence and Disappearance of Feudalism
Feudalism traditionally emerges as a result of the decentralization of an empire. This was particularly the case within the Japanese and Carolingian (European) empires which both lacked the bureaucratic infrastructure necessary to support cavalry without the ability to allocate land to these mounted troops. Mounted soldiers began to secure a system of hereditary rule over their allocated land and their power over the territory came to encompass the social, political, judicial, and economic spheres as well. These acquired powers significantly reduced the presence of centralized power in these empires. Only when the infrastructure existed to maintain centralized power--as with the European monarchies--did Feudalism begin to yield to this new organized power and eventually disappear.

完全自治，封建主也就是伯爵、公爵、教主对管辖具有司法、经济、军事的独立统治权力。地方与皇帝唯一的联系是他们实质上是一个军事共同体，为了抵御外界侵略会集中军事力量。那时情况就像中国民国军阀混战一样。当时经济是采邑制，很剥削人的一种利用保护人民生命财产安全的名义剥削人的一种制度。

西罗马帝国灭亡以后,日耳曼民族建立了很多国家,如法兰克王国,这个国家后来发展成为查理曼帝国,后分裂为三个国家,成为法兰西,德意志和意大利的雏形,它们与同时出现的英吉利王国一起,成为欧洲早期的主要封建国家.这些国家在发展过程中同时实现了奴隶制度向封建制度的转变.
封建庄园制度,封建农奴制度和封建等级制度,以及基督教的作用和影响成为当时欧洲中世纪封建制度的最大特点

类似于我国西周的分封制；

《中国通史简编》中把西周分封制直接看作欧洲中世纪法兰克封建采邑制,把西周与其分封的诸侯国等量齐观。
1、中世纪西欧法兰克封建采邑制：金字塔型统治结构：王下面由大到小公侯伯子男爵、最后是骑士阶层；
中国西周也是金字塔型统治结构：周王、诸侯、士大夫、家臣。

2、西欧采邑制也好中国西周分封制也好都是靠土地为纽带维系。

我觉得是中国的分封制。。。
因为中世纪的封建制度是：封建庄园制度。堡主为最高统治者，有管辖权。而我国的分封制有点类似于它。地方最高统治者是诸侯。有管辖权。