确定性是人类的重要追求，不确定是确定性的土壤和家园。城市始终游走在确定性与不确定性之间。一方面，人们进入城市是为了更好的生活，通过城市发展、城市更新，人们获得了更多、更为综合的确定性；另一方面，城市又始终面临着各种不确定性，既有来自外部自然的灾难、风险，也有来自社会关系、生产方式、交往方式、文化观念等方面不可预见的突发事件。在时间与空间、速度与尺度、对象与感知的统一中，城市化既是一个确定性增长的过程，也是一个不确定性增长的过程。城市社会面临的不确定性主要有：生态与存在维度的不确定性、传承与秩序维度的不确定性、发展与进步维度的不确定性、情感与意义维度的不确定性。治理理念不尽合理、治理体系不尽完善、治理行为不尽规范，是城市社会不确定性增强的重要原因。民生与发展、科学与专业、弹性与张力，是现代城市治理需要坚守的基本原则。树立具有不确定性底蕴的治理观念、治理体系，尊重、包容多样主体的自组织创新，对于城市社会的良性可持续发展具有路径意义。

Certainty is an important pursuit of human beings, while uncertainty is the soil and home of certainty. Cities always wander between certainty and uncertainty. In the unity of time and space, speed and scale, and object and perception, urbanization is a process of both deterministic and uncertain growth. The uncertainties faced and encountered by urban society are mainly: uncertainty in the ecological and existence dimension, the heritage and order dimension, the development and progress dimension, the emotion and meaning dimension. The notion of governance is not as reasonable, the governance system is not as perfect, and the governance behavior is not as standardized, which are important causes of the increased uncertainty in urban society. People’s livelihood and development, science and professionalism, flexibility and tension are the basic principles that modern urban governance needs to adhere to. Establishing a governance concept and governance system with uncertainty undertones, and respecting and accommodating the self-organized innovation of diverse subjects are of pathological significance for the benign sustainability of urban society.